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Nanostructured Materials

RESEARCH

DEPARTMENTS
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RESEARCH GROUPS
Atomic
Nanostructured_Rale

HIGHLIGHTS

July 2018: Sharath successfully completed his Masters Thesis Defense (Thesis Title: Electron Microscopy and Spectroscopy Study of Modified Titanate Nanowires and Nanotubes)

July 2018: FCT Funded Project: Correlated Analysis of Inorganic Solar Cells in and outside an Electron Microscope (CASOLEM) (http://inl.int/funded-projects/) has started.

July 2018: Leonard gave an Invited Talk in ANM-2018 (http://www.advanced-nanomaterials-conference.com/speakers/)

July 2018: Paper Published in Advanced Science

In situ Atomic-Scale Study of Particle-Mediated Nucleation and Growth in Amorphous Bi to Nanocrystal Phase Transformation, Junjie Li, Jiangchun Chen, Hua Wang, Na Chen, Zhongchang Wang, Lin Guo and Francis Leonard Deepak, Adv. Sci., 2018, 1700992; DOI: 10.1002/advs.201700992.

June 2018: Junjie Li presented his work in SCANDEM-2018(http://www.cen.dtu.dk/english/scandem-2018/)

June 2018: Paper published in J.Man.Process

Multilevel Process on Large Area Wafers for Nanoscale Devices, B. J. Pires, A. V. Silva, A. Moskaltsova, F. L. Deepak, P. Brogueira, D. C. Leitao, S. Cardoso, J. Manufacturing Processes, 2018, 32, 222-229.

May 2018: Best Poster Award – First Prize (Workshop on Electron Microscopy May 4th 2018, INL)

Poster: Single Walled BiI3 and GdI3 Nanotubes Encapsulated within CNT, A. Anumol, Nitin M. Batra, Pedro M. F. J. Costa, Andrey N. Enyashin and Francis Leonard Deepak

April 2018: Paper published in Appl.Surf.Sci

Biocompatible Au@Carbynoid/Pluronic-F127 nanocomposites synthesized by pulsed laser ablation assisted CO2 recycling, T. Del Rosso, S.R.W. Louro, F.L.  Deepak, et al. Appl Surf. Sci., 2018, 441, 347-355.

March 2018: Paper published in J. Phys. Chem. Lett

Direct Atomic-Scale Observation of Intermediate Pathways of Melting and Crystallization in Supported Bi-Nanoparticles, Junjie Li, Zhongchang Wang and Francis Leonard Deepak, J. Phys. Chem. Lett., 2018, 9, 961-969.

February 2018: Paper published in J. Phys. Chem. C

Atomic-Scale Understanding of Gold Cluster Growth on Different Substrates and Adsorption-Induced Structural Change, Qiang Li, Deqiang, Yin, Junjie Li, and Francis Leonard Deepak, J. Phys. Chem. C, 2018, 122, 1753-1760.

January 2018: New Book Published by Springer

BookCover

DESCRIPTION

The Nanostructured Materials group is involved in investigating fundamental aspects and phenomena at the atomic scale. This is achieved by employing state of the art aberration corrected TEM/STEM imaging and In situ experimentation in combination with image processing, simulations and theoretical calculations. The group has a set of focused and passionate researchers working on current key topics towards implementing advanced electron microscopy techniques and their applications to a variety of nanomaterials, thin films, nanodevices etc. Some of the key materials investigated include energy related and catalytically important materials; the emphasis being on correlating their atomic structure and chemical composition with their properties and potential applications. Understanding the atomic structure of materials is fundamental to exploring their various interesting properties: magnetic, optical and optoelectronic and this is achieved by carrying out aberration corrected S/TEM imaging in combination with analytical electron microscopy.

We also have several current and ongoing collaborations with international researchers who are leading experts in the field.

Some of the ongoing work of the group include:

  • Implementation of aberration corrected techniques towards the investigations of nanomaterials and nanodevices
  • Investigations of low dimensional materials
  • Metal Nanoparticles and clusters
  • Implementing Tomography-Spectroscopy based techniques for simultaneous structural-morphological-chemical composition analysis of complex nanomaterials in 3D
  • Exploration of novel phases of materials encapsulated within Nanotubes and related nanocavities
  • Investigation of defects in materials
  • In situ transmission electron microscopy to understand nucleation and growth of solid-liquid phases at the interface

Our work is published in leading international journals and include several review articles, book chapters and edited books.

We are always open for new team members. If you are interested in joining the team and applying for external funding (i.e. Marie Curie, FCT, etc.), let us know.

For further queries please contact the Research Group Leader: Leonard Deepak Francis (leonard.francis@inl.int).

RESEARCH PROJECTS

People in this Project: Junjie Li and Francis Leonard Deepak

In situ observation of the lattice induced growth of nanocrystals on substrate

CrystGrowDes_picture

Uncovering dynamical processes of lattice induced epitaxial growth of nanocrystal on the support is critical to understanding crystallization, solid-phase epitaxial growth, Oswald ripening process, and advanced nanofabrication, all of which are linked to different important applications in material field. Here, we conduct direct in-situ atomic-scale dynamical observation of segregated Bi layers on SrBi2Ta2O9 support under low dose electron irradiation to explore the nucleation and growth from an initial disordered solid state to a stable faceted crystal by using aberration corrected transmission electron microscopy (AC-TEM). We have provided, for the first time, atomic-scale insights into the initial pre-nucleation stage of lattice induced interfacial nucleation, size-dependent crystalline fluctuation and stepped growth stage of the formed nanocrystal on the oxide support at the atomic scale. We identify a critical diameter in forming a stable faceted configuration and find interestingly that the stable nanocrystal presents a size-dependent coalescence mechanism. These results offer an atomic-scale view into dynamic process at solid/solid interfaces, which has implications for thin film growth and advanced nanofabrication.

In situ observation of Droplets Coalescence Driven Nucleation and Growth at Liquid/Solid Interface

ACSNano_picture

Unravelling dynamical processes of liquid droplets at liquid/solid interfaces and the interfacial ordering is critical to understanding solidification, liquid-phase epitaxial growth, wetting, liquid-phase joining, crystal growth, and lubrication process, all of which are linked to different important applications in material science. In this work, we observe direct in-situ atomic-scale behaviour of Bi droplets segregated on SrBi2Ta2O9 by using aberration corrected transmission electron microscopy and demonstrate ordered interface and surface structures for the droplets on the oxide at the atomic-scale and unravel a nucleation mechanism involving droplet coalescence at the liquid/solid interface. We identify a critical diameter of the formed nanocrystal in stabilizing the crystalline phase and reveal lattice induced fast crystallization of the droplet at the initial stage of the coalescence of nanocrystal with droplet. Further sequential observations show the stepped coalescence and growth mechanism of the nanocrystals at the atomic-scale. These results offer insights into the dynamic process at liquid/solid interfaces, which may have implications for many functionalities of materials and their applications.

Direct Atomic-Scale Observation of Intermediate Pathways of Melting and Crystallization in Supported Bi-Nanoparticles

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Uncovering the evolutional pathways of melting and crystallization atomically is critical to understanding complex microscopic mechanism of first-order phase transformation. Here, we conduct in-situ atomic-scale observations of melting and crystallization in supported Bi-nanoparticles under heating and cooling within an aberration-corrected TEM. We provide direct evidence to the multiple intermediate state events in melting and crystallization. The melting of the supported nanocrystal involves the formation and migration of domain boundaries and dislocations due to the atomic rearrangement under heating, which occurs through a size-dependent multiple intermediate state. A critical size, which is key to inducing the transition pathway in melting from two to four barriers, is identified for the nanocrystal. In contrast, crystallization of a Bi droplet involves three stages. These findings demonstrate that the phase transformations cannot be viewed as a simple single barrier- crossing event but as a complex multiple intermediate state phenomenon, highlighting the importance of nonlocal behaviors.

In situ Atomic-Scale Study of Particle Mediated Nucleation and Growth in Amorphous Bi to Nanocrystal Phase Transformation

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Understanding classical and non-classical mechanisms of crystal nucleation and growth at the atomic scale has been of great interest to scientists in many disciplines. However, fulfilling direct atomic-scale observation still poses a significant challenge. Here, by taking a thin amorphous Bi metal nanosheet as a model system, we provide direct atomic resolution of the crystal nucleation and growth initiated from an amorphous state of Bi metal under electron beam inside an aberration corrected transmission electron microscope. We show that the crystal nucleation and growth in the phase transformation of Bi metal from amorphous to crystalline structure takes place via the particle-mediated non-classical mechanism instead of the classical atom-mediated mechanism. The dimension of the smaller particles in two contacted nanoparticles and their mutual orientation relationship are critical to governing several coalescence pathways: total rearrangement pathway, grain boundary migration dominated pathway and surface migration dominated pathway. Sequential strain analyses imply that migration of grain boundary is driven by strain difference in two Bi nanocrystals and the coalescence of nanocrystals is a defect reduction process. The findings may provide useful information on clarifying nanocrystal growth mechanisms of other materials at the atomic scale.

External Collaborations:

Dr. Qiang Li (School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China).

C. Chen, Dr. H. Wang, and Prof. L. Guo (School of Chemistry and Environment, Beihang University Beijing 100191, China).

Prof. N. Chen (School of Materials Science and Engineering Tsinghua University Beijing 100084, China).

Dr. Zhongchang Wang (Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan).

Publications

  • In situ Atomic-Scale Study of Particle-Mediated Nucleation and Growth in Amorphous Bi to Nanocrystal Phase Transformation, Junjie Li, Jiangchun Chen, Hua Wang, Na Chen, Zhongchang Wang, Lin Guo and Francis Leonard Deepak, Adv. Sci., 2018, 1700992; DOI: 10.1002/advs.201700992.
  • Direct Atomic-Scale Observation of Intermediate Pathways of Melting and   Crystallization in Supported Bi-Nanoparticles, Junjie Li, Zhongchang Wang and Francis Leonard Deepak, J. Phys. Chem. Lett., 2018, 9, 961-969.
  • In Situ Atomic-Scale Observation of Droplet Coalescence Driven Nucleation and Growth at Liquid/Solid Interfaces, Junjie Li, Zhongchang Wang, and Francis Leonard Deepak, ACS Nano, 2017, 11 (6), pp 5590–5597.
  • Real-Time Dynamical Observation of Lattice Induced Nucleation and Growth in Interfacial Solid-Solid Phase Transitions, Junjie Li, Qiang Li, Zhongchang Wang, and Francis Leonard Deepak, Cryst. Growth Des., 2016, 16, 7256−7262.

People in this Project: E.A. Anumol and Francis Leonard Deepak

The hollow interior core of nanotubes, both carbon and non-carbon (BN, WS2 etc.) provide the necessary space for the filling, encapsulation and confinement of molecules and crystals both organic and inorganic. In addition they provide templates for the formation of core-shell nanotubes. The reduced dimensionality of the encapsulated material as a consequence of “confinement” presents the advantage of different characteristics compared to that of the bulk material. The interaction between the encapsulated material and the host nanotube plays a crucial role and therefore can govern the structure and electronic properties of such a system.
In this project nanotubes (CNTs as well as Inorganic NTs) which provide accessible space for templated growth of nanotubes or nanorods within them are employed to encapsulate metal halides such as GdI3 and BiI3 which are contrast agents for biomedical imaging. Capillary filling is employed to encapsulate these metal halides within nanotubes of carbon and WS2 to obtain core-shell nanotubes and/or nanorods. Aberration Corrected Scanning/Transmission Electron Microscopy and Spectroscopy using the Titan G2 80-200 TEM/STEM with ChemiSTEM Technology and FEI Titan Themis 60-300 kV is employed to characterize the atomic structure, morphology and composition of these core-shell structures.

Project2_pictureExternal Collaborations
Dr. Pedro Costa and Mr. Nitin M. Batra (KAUST, Saudi Arabia)

Dr. Andrey Enyashin: Molecular Dynamics Simulation (Ural Federal University, Institute of Natural Sciences and Mathematics, Ekaterinburg, Russian Federation).

Publications

(1) Nitin M. Batra, E. A. Anumol, Jasmin Smajic, Andrey N. Enyashin, Francis Leonard Deepak and Pedro M. F. J. Costa, Morphological phase diagram of a metal halide encapsulated in carbon nanotubes, Submitted 2018.

(2) Capillary Imbibition of Gadolinium Halides into WS2 Nanotubes: A Molecular Dynamics, Francis Leonard Deepak and A. N. Enyashin, Isr. J. Chem, Special Issue: Computational Science of Inorganic Nanostructures, 2017, 57, 501-508.

(3) Structural and chemical analysis of gadolinium halides encapsulated within WS2 nanotubes, E. A. Anumol, A. N. Enyashin, N. M. Batra, P. M. F. J. Costa and Francis Leonard Deepak, Nanoscale, 2016, 8, 12170-12181.

People in this Project: E.A. Anumol and Francis Leonard Deepak

In this project HAADF-STEM tomography is employed to obtain the 3D morphology of nanomaterials such as nanocatalysts and core-shell nanotubes. A Titan G2 80-200 TEM/STEM with ChemiSTEM Technology is used for this. EDX-STEM tomography is employed to obtain 3D chemical mapping. Low accelerating voltage (80 kV) enables tomography of beam sensitive materials such as carbon nanotubes. A high tilt tomography holder  and Super-X EDS detector (in the Titan ChemiSTEM) comprising four SDD detectors enable the EDX mapping in a wide tilt range (-70° to +70°) . Inspect 3D software is used for reconstruction and Amira for visualization.

Project3_pictureExternal Collaborations

Dr. Pedro Costa and Mr. Nitin M. Batra (KAUST, Saudi Arabia)

Dr. Andrey Enyashin – Molecular Dynamics Simulation (Institute of Solid State Chemistry UB RAS Ekaterinburg, RUSSIAN FEDERATION).

Dr. C.P.VinodCSIR-National Chemical Laboratory, India

Publications

(1) Structural and chemical analysis of gadolinium halides encapsulated within WS2 nanotubes, E. A. Anumol, A. N. Enyashin, N. M. Batra, P. M. F. J. Costa and Francis Leonard Deepak, Nanoscale, 2016, 8, 12170-12181.

(2) A Convenient Route for Au@Ti-SiO2 Nanocatalyst Synthesis and its Application for Room Temperature CO Oxidation, A. Yogitha Soni, E. A. Anumol, Chandrani Nayak Francis Leonard Deepak, C. P. Vinod, Chathakudath, Phys. Chem. C 2017, 129, 4946-4957.

People in this Project: Markus Snellman, Irene Bechis, Joao Freitas, E.A. Anumol, Junjie Li and Francis Leonard Deepak

NJC.jpg

Monometallic, Bimetallic and multimetallic core-shell nanoparticle/nanowire catalysts of noble metal alloys possesses superior activity, high selectivity and stability at low temperature compared to traditional bulk metals. This makes them ideal candidates for carrying out investigations on their structure, nature of alloy formation and thus understand the way the catalytic activity is enhanced. Direct microscopic studies of various bimetallic nanoparticles have been carried out using high-resolution transmission electron microscopy (HRTEM). However, this method is limited because of the small difference in the lattice constant involved. Conventional transmission electron microscopy (CTEM) can produce chemical contrast due to due to different electron beam extinction distances. This has been applied successfully to image bimetallic nanoparticles down to 10 nm in diameter. Since the particles need to be in a low index zone orientation, this method is not easy to use in practice. As an alternative method of nanostructure determination high angle angular dark field (HAADF) imaging technique has been used successfully. The HAADF method has been used to detect variation in chemical composition down to single atom level in structures of nanosized particles. STEM-HAADF imaging carried out in an aberration corrected microscope reveals the atomistic structure and the alloying of bimetallic nanoparticles and nanowires. In combination with high resolution spectral and chemical analysis this techniques provides unprecedented information never obtained till date. Understanding the nature and structure of such bimetallic/multimetallic nanocatalysts is important to enable modification of their structure/morphology/composition and enhance their catalytic performance for fuel cells and other industrial applications.

External Collaborations

Prof. M. Arturo López-Quintela (Dept. Physical Chemistry, Faculty of Chemistry Lab of Nanotechnology and Magnetism (NANOMAG) Research Technological Institute University of Santiago de Compostela)

Dr. P. John Thomas (School of Chemistry, Bangor University, Bangor, UK)

Prof. Maurizio Muniz-Miranda (“Ugo Schiff” Chemistry Dept, University of Florence)

Dr. Roberto Pilot (Consorzio INSTM and Department of Chemical Sciences, via Marzolo 1, 35131 Padova, Italy)

Dr. C.P. Vinod (Catalysis Division and Center of Excellence on Surface Science, CSIR National Chemical Laboratory, Pune, INDIA)

Dr. R. Nandini Devi (Catalysis Division, National Chemical Laboratory, Pune, India)

Dr. Qiang Li (School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China)

Dr. Deqiang Yin (School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China and Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan)

T. Del Rosso, Department of Physics, Pontifi­cia Universidade Catolica do Rio de Janeiro, Brazil

Book Chapters

  • Advanced Electron Microscopy Techniques Towards the Understanding of Metal Nanoparticles and Clusters, Francis Leonard Deepak, E.A. Anumol, Junjie Li, Book: Metal Nanoparticles and Clusters: Recent Advances in the synthesis, properties and applications (Springer), Ed: Francis Leonard Deepak (2018).
  • Advanced Methods of Electron Microscopy in Catalysis Research, Miguel Jose-Yacaman, Arturo Ponce-Pedraza, Sergio Mejia-Rosales and Francis Leonard Deepak, Advances in Imaging & Electron Physics (Academic Press), Editor: Peter Hawkes, vol. 177, pp: 279-342 (2013).

Edited Book

BookCover

Metal Nanoparticles and Clusters Advances in Synthesis, Properties and Applications, Ed: Francis Leonard Deepak, Springer 2018.

Publications

(1) Biocompatible Au@Carbynoid/Pluronic-F127 nanocomposites synthesized by pulsed laser ablation assisted CO2 recycling, T. Del Rosso, S.R.W. Louro, F.L. Deepak, E.C. Romani, Q. Zaman, Tahir, O. Pandoli, M. Cremona, F.L. Freire Junior, P. De Buele, T. De St. Pierre, R.Q. Aucelio, G. Mariotto, S. Gemini- Piperni, A.R. Ribeiro, S.M. Landi, A. Magalhaes, Appl. Surf. Sci., 2018, 441, 347-355.

(2) Qiang Li, Deqiang, Yin, Junjie Li, and Francis Leonard Deepak, Atomic-Scale Understanding of Gold Cluster Growth on Different Substrates and Adsorption-Induced Structural Change, J. Phys. Chem. C 2018, 122, 1753-1760.

(3) Magnetic Nanoparticles obtained by two-step Laser Ablation of Nickel and Silver in pure Water, Cristina Gellini, Francis Leonard Deepak, Maurizio Muniz-Miranda, Stefano Caporali, Francesco Muniz-Miranda, Alfonso Pedone, Claudia Innocenti, Claudio Sangregorio, J. Phys. Chem. C 2017, 121, 3597-3606.

(4) A convenient route for Au@Ti-SiO2 nanocatalyst synthesis and its application for room temperature CO oxidation, Yogita Sonia, A. Anumol, Chandrani Nayak, Francis Leonard Deepak, C.P. Vinod, J. Phys. Chem. C 2017, 129, 4946-4957.

(5) Understanding alloy structure and composition in sinter-resistant AgPd@SiO2 encapsulated catalysts and their effect on catalytic properties, Sourik Mondal, Thattarathody Rajesh, Basab B. Dhar, Markus Snellman, Junjie Li, Francis Leonard Deepak and R. Nandini Devi, New J. Chem., 2017, 41, 14652.

(6) Controlling Bimetallic Nanostructures by the Microemulsion Method with Subnanometer Resolution Using a Prediction Model, David Buceta, Concha Tojo, Miomir Vukmirovic, Francis Leonard Deepak, Arturo M. Lopez-Quintela, Langmuir, 2015, 31, 7435-7439.

(7) Wavelength dispersion of the local field intensity in silver–gold nanocages, R. Pilot, Zoppi, S. Trigari, F. L. Deepak, E. Giorgetti and R. Bozio, Phys. Chem. Chem. Phys., 2015, 17, 7355.

(8) Stable Ruthenium colloids by Laser Ablation, Brandi, S. Caporali, S. Cicchi, L. Lascialfari, M. Muniz-Miranda, S. Orazzini, M. Severi, Francis Leonard Deepak and E. Giorgetti, IEEE NANO, July 2015.

People in this Project: Junjie Li and Francis Leonard Deepak

Doping is an effective method to tune the electronic properties for MoS2 as well as other 2D semiconductors and has significant implications on their optical and electronic properties. In this project we fabricate doped MoS2 samples with different dopants and/or doping concentrations and study them employing high resolution imaging and spectroscopy.

External Collaborations:

Dr. G. Deokar (University of Namur, Belgium)

Publications

  • G. Deokar, J. J. Li, F. L. Deepak, W. Ou-Yang, N. Reckinger, C. Bittencourt, J.-F. Colomer, M. Jouaid, Field emission properties of vertically aligned MoS2 NSs, Submitted, 2017.

People in this Project: Sharath Kumar and Francis Leonard Deepak

Project6_pictureThe study is aimed at employing electron microcopy in combination with spectroscopic techniques to study these materials and provide an accurate and in-depth understanding into the various aspects related to their catalytic activity. The samples under consideration are transition metal modified TNTs which are prepared by cation exchange of the hydrothermally synthesized TNTs as well as doped TNTs. The techniques include employing Aberration Corrected Electron Microscopy (AC-TEM/STEM) along with the associated spectroscopic techniques, Electron Energy Loss Spectroscopy (EELS) and Energy Dispersive X-Ray Spectroscopy (EDX), as this could provide the structure, composition and morphology of the specimen in a single experiment, from the same region, with high spatial resolution. Of particular importance would be the identification of the cations that are incorporated as dopants (and/or intercalated) and imaging them with single-atom sensitivity, along with elucidation of their oxidation/bonding states of undoped and doped samples (Ti4+ vs Co2+). It is expected that such a detailed experimental study using electron microscopy would provide new insights into the structural and compositional aspects which influences the catalytic properties.

External Collaborations:

Dr. Anabela Rolo (Dept. Physics, U. Minho, Braga, Portugal)

ONGOING NATIONAL AND EUROPEAN PROJECTS

  • N2020: Nanotechnology based functional solutions (NORTE-45-2015-02). Duration: 2016-2018

Previous National and European Projects

  • Regulatory testing of nanomaterials (NANoREG), FP7 Nanotechnologies & Nanosciences Thematic Cooperation Programme, Participant, Duration: 2013-2017.
  • WATERNANOENV (National Project), Axencia Galega de Innovacion  (GAIN)-ERDF Partners: Instituto Tecnologico de Galicia (ITG)-coordinator, Universidade de Santiago de Compostela (USC)-subcontracted and INL-subcontracted, Duration: 2015-2017.
  • NANO-HVAC: Novel Nano-enabled Energy Efficient and Safe HVAC ducts and systems contributing to an healthier indoor environment,  FP7 – Seventh Framework Programme, Duration: 2012-2015.
  • ON2-ERDF: Project Title – Self-assembled functionalized nanomaterials for biomolecular recognition, Call: SAESCTN-PIIC&DT/1/2011, Duration: 2013-2015.

NATIONAL AND INTERNATIONAL COLLABORATIONS

  • University of Minho (Portugal)
  • CICECO – University of Aveiro (Portugal)
  • INESC-MN (Portugal)
  • USC – University of Santiago de Compostela (Spain)
  • University of Florence (Italy)
  • KAUST (Saudi Arabia)
  • University of Bangor(U.K.)
  • NCL Pune (India)
  • Ural Federal University (Russian Federation)
  • UT-Austin (USA)
  • Weizmann Institute of Science (Israel)

PUBLICATIONS

2017

Nitin M. Batra E. A. Anumol, Jasmin Smajic Andrey Enyashin Francis Leonard Deepak; Costa, Pedro

Morphological phase diagram of a metal halide encapsulated in carbon nanotubes (Journal Article)

Submitted, 2017.

(BibTeX)

Yogita Sonia E.A. Anumol, Chandrani Nayak Francis Leonard Deepak Vinod Phys

A convenient route for Au@Ti-SiO2 nanocatalyst synthesis and its application for room temperature CO oxidation (Journal Article)

Chem. C , 129 (4946-4957), 2017.

(BibTeX)

Sourik Mondal Thattarathody Rajesh, Basab Dhar Markus Snellman Junjie Li Francis Leonard Deepak Nandini Devi

Understanding alloy structure and composition in sinter-resistant AgPd@SiO2 encapsulated catalysts and their effect on catalytic properties (Journal Article)

Submitted , 2017.

(BibTeX)

Cristina Gellini Francis Leonard Deepak, Maurizio Muniz Miranda Stefano Caporali Francesco Muniz-Miranda Alfonso Pedone Claudia Innocenti; Claudio Sangregorio, Phys

Magneto-Plasmonic Colloidal Nanoparticles Obtained by Laser Ablation of Nickel and Silver Targets in Water (Journal Article)

Chem. C, (121), pp. 3597−3606, 2017.

(BibTeX)

Junjie Li Zhongchang Wang, Francis Leonard Deepak

In-situ Atomic-scale Observation of Droplets Coalescence Driven Nucleation and Growth at Liquid/Solid Interface (Journal Article)

Submitted, 2017.

(BibTeX)

2016

E. A. Anumol A. N. Enyashin, Batra Costa; Deepak, Francis Leonard

Structural and chemical analysis of gadolinium halides encapsulated within WS2 nanotubes (Journal Article)

Nanoscale, (8), pp. 12170-12181, 2016.

(BibTeX)

Deepak, Francis Leonard; Enyashin,

Capillary Imbibition of Gadolinium Halides into WS2 Nanotubes: A Molecular Dynamics View (Journal Article)

Isr. J. Chem., 2016.

(Links | BibTeX)

Junjie Li Qiang Li, Zhongchang Wang; Deepak, Francis Leonard

Real-Time Dynamical Observation of Lattice Induced Nucleation and Growth in Interfacial Solid-Solid Phase Transitions (Journal Article)

Cryst. Growth Des., Just Accepted Manuscript, 2016.

(Links | BibTeX)

J. Rodrigo Magana Yury V. Kolen’ko, Francis Leonard Deepak Conxita Solans Rekha Goswami Shrestha Jonathan Hill Katsuhiko Ariga Lok Kumar Shrestha; Rodriguez-Abreu, Carlos

From Chromonic Self-Assembly to Hollow Carbon Nanofibers for Efficient Materials in Supercapacitor and Vapor Sensing Applications (Journal Article)

ACS Applied Materials & Interfaces, 2016.

(Links | BibTeX)

2015

Francis Leonard Deepak Manuel Bañobre-López, Enrique Carbó-Argibay Fátima Cerqueira Yolanda Piñeiro-Redondo JoséRivas Corey Thompson Saeed Kamali Carlos Rodríguez-Abreu Kirill Kovnir; Kolenko, Yury

A Systematic Study of the Structural and Magnetic Properties of Mn‑, Co‑, and Ni-Doped Colloidal Magnetite Nanoparticles (Journal Article)

J. Phys. Chem C, (119), pp. 11947-11957, 2015.

(BibTeX)

David Buceta Concha Tojo, Miomir Vukmirovic Francis Leonard Deepak Arturo Lopez-Quintela

Controlling Bimetallic Nanostructures by the Microemulsion Method with Subnanometer Resolution Using a Prediction Model (Journal Article)

Langmuir, (31), pp. 7435-7439, 2015.

(BibTeX)

Eunice Cunha M. Fernanda Proença, Florinda Costa António Fernandes Marta Ferro Paulo Lopes Mariam Debs Manuel Melle-Franco Francis Leonard Deepak Maria Paiva

Self-assembled functionalized graphene nanoribbons from carbon nanotubes (Journal Article)

ChemistryOpen, (4), pp. 115 – 119, 2015.

(BibTeX)

Maryam Salimian Maxim Ivanov, Francis Leonard Deepak Dmitri Petrovykh Igor Bdikin Marta Ferro Andre Kholkin Elby Titus; Goncalves, Gil

Synthesis and characterization of reduced graphene oxide /spiky nickel nanocomposites for nanoelectronic applications (Journal Article)

J. Mater. Chem. C, (3), pp. 11516 – 11523, 2015.

(BibTeX)

R. Pilot A. Zoppi, Trigari Deepak Giorgettib; Bozioa,

Wavelength dispersion of the local field intensity in silver–gold nanocages (Journal Article)

Phys.Chem.Chem.Phys., (17), pp. 7355, 2015.

(BibTeX)

Nitin M Batra Shashikant P Patole, Ahmed Abdelkader Dalaver Anjum Francis Deepak; Costa, Pedro

Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices (Journal Article)

Nanotechnology, (26), pp. 445301, 2015.

(BibTeX)

J. D. Costa S. Serrano-Guisan, Borme Deepak Tarequzzaman Paz J.Ventura Ferreira; Freitas,

Impact of MgO thickness on the performance of Spin Transfer Torque Nano-Oscillators​ (Journal Article)

IEEE Trans. Magn, (52), pp. 1401604, 2015.

(BibTeX)

2014

Francis Leonard Deepak Jose Rivas, Miguel Jose-Yacaman

Understanding the structure of nanocatalysts with High Resolution Scanning/ Transmission Electron Microscopy (Journal Article)

IOP Conf. Ser.: Mater. Sci. Eng, (55), pp. 012005 , 2014.

(BibTeX)

Stephanie Vial Dmytro Nykypanchuk, Francis Leonard Deepak Marta Prado; Gan, Oleg

Plasmonic response of DNA-Assembled Gold Nanorods (AuNRs) (Journal Article)

Journal of Colloid and Interface Science, (433), pp. 34-42, 2014.

(BibTeX)

Yury V. Kolen’ko Manuel Bañobre-López, Carlos Rodríguez-Abreu Enrique Carbó-Argibay Francis Leonard Deepak Dmitri Petrovykh Fátima Cerqueira Saeed Kamali Kirill Kovnir Dmitry Shtansky Oleg Lebedev; Rivas, Jose

High-Temperature Magnetism as a Probe for Structural and Compositional Uniformity in Ligand-Capped Magnetite Nanoparticles (Journal Article)

J. Phys. Chem. C , (118), pp. 28322−28329, 2014.

(BibTeX)

Ana V. Silva Diana C. Leitao, Ricardo Ferreira Elvira Paz Francis Leonard Deepak Susana Cardoso; Freitas, Paulo

Linear nanometric tunnel junction sensors with exchange pinned sensing layer (Journal Article)

Journal of Applied Physics, (115), pp. 17E526, 2014.

(BibTeX)

Diana C. Leitao Elvira Paz, Ana Silva Anastasiia Moskaltsova Simon Knudde Francis Deepak Ricardo Ferreira Susana Cardoso; Freitas, Paulo

Nanoscale Magnetic Tunnel Junction sensing devices with soft pinned sensing layer and low aspect ratio (Journal Article)

IEEE Transactions on Magnetics, 50 , pp. 4410508, 2014.

(BibTeX)

GROUP LEADER

Leonard_Francis

THE TEAM

Anumol Ashokkumar (Aug 2015 – present)
Research Fellow

Junjie Li (Jan 2016 – present)
Research Fellow

Sharath Kumar 
Master Student (Sep 2016 – present)

Oliver Armstrong
Scientific Visitor (University of Bangor, UK) (Jan-Feb 2018)

Cherrelle Thomas 
Scientific Visitor (UT-Austin, USA) (July 2017)

Dr. John Thomas 
Scientific Visitor (University of Bangor, UK) (August 2017)

Tiago Miguel Pereira Rebelo
Summer Student (June – Aug 2018)

Irene Bechis 
Summer Student (July – Sep 2017)

Joao Freitas
Summer Student (July – Sep 2017)

Markus Snellman
Summer Student (July – Aug 2016)

GROUP LEADER

Leonard_Francis

THE TEAM

Anumol Ashokkumar (Aug 2015 – present)
Research Fellow

Junjie Li (Jan 2016 – present)
Research Fellow

Sharath Kumar 
Master Student (Sep 2016 – present)

Oliver Armstrong

Scientific Visitor (University of Bangor, UK) (Jan-Feb 2018)

Cherrelle Thomas 
Scientific Visitor (UT-Austin, USA) (July 2017)

Dr. John Thomas 
Scientific Visitor (University of Bangor, UK) (August 2017)

Tiago Miguel Pereira Rebelo
Summer Student (June – Aug 2018)

Irene Bechis 
Summer Student (July – Sep 2017)

Joao Freitas
Summer Student (July – Sep 2017)

Markus Snellman
Summer Student (July – Aug 2016)

DESCRIPTION

The Nanostructured Materials group is involved in investigating fundamental aspects and phenomena at the atomic scale. This is achieved by employing state of the art aberration corrected TEM/STEM imaging and In situ experimentation in combination with image processing, simulations and theoretical calculations. The group has a set of focused and passionate researchers working on current key topics towards implementing advanced electron microscopy techniques and their applications to a variety of nanomaterials, thin films, nanodevices etc. Some of the key materials investigated include energy related and catalytically important materials; the emphasis being on correlating their atomic structure and chemical composition with their properties and potential applications. Understanding the atomic structure of materials is fundamental to exploring their various interesting properties: magnetic, optical and optoelectronic and this is achieved by carrying out aberration corrected S/TEM imaging in combination with analytical electron microscopy.

We also have several current and ongoing collaborations with international researchers who are leading experts in the field.

Some of the ongoing work of the group include:

  • Implementation of aberration corrected techniques towards the investigations of nanomaterials and nanodevices
  • Investigations of low dimensional materials
  • Metal Nanoparticles and clusters
  • Implementing Tomography-Spectroscopy based techniques for simultaneous structural-morphological-chemical composition analysis of complex nanomaterials in 3D
  • Exploration of novel phases of materials encapsulated within Nanotubes and related nanocavities
  • Investigation of defects in materials
  • In situ transmission electron microscopy to understand nucleation and growth of solid-liquid phases at the interface

Our work is published in leading international journals and include several review articles, book chapters and edited books.

We are always open for new team members. If you are interested in joining the team and applying for external funding (i.e. Marie Curie, FCT, etc.), let us know.

For further queries please contact the Research Group Leader: Francis Leonard Deepak (leonard.francis@inl.int).

RESEARCH PROJECTS

Atomic scale study of the nucleation and growth mechanisms of nanocrystals and their thermal stability

People in this Project: Junjie Li and Francis Leonard Deepak

In situ observation of the lattice induced growth of nanocrystals on substrate

CrystGrowDes_picture

Uncovering dynamical processes of lattice induced epitaxial growth of nanocrystal on the support is critical to understanding crystallization, solid-phase epitaxial growth, Oswald ripening process, and advanced nanofabrication, all of which are linked to different important applications in material field. Here, we conduct direct in-situ atomic-scale dynamical observation of segregated Bi layers on SrBi2Ta2O9 support under low dose electron irradiation to explore the nucleation and growth from an initial disordered solid state to a stable faceted crystal by using aberration corrected transmission electron microscopy (AC-TEM). We have provided, for the first time, atomic-scale insights into the initial pre-nucleation stage of lattice induced interfacial nucleation, size-dependent crystalline fluctuation and stepped growth stage of the formed nanocrystal on the oxide support at the atomic scale. We identify a critical diameter in forming a stable faceted configuration and find interestingly that the stable nanocrystal presents a size-dependent coalescence mechanism. These results offer an atomic-scale view into dynamic process at solid/solid interfaces, which has implications for thin film growth and advanced nanofabrication.

In situ observation of Droplets Coalescence Driven Nucleation and Growth at Liquid/Solid Interface

ACSNano_picture

Unravelling dynamical processes of liquid droplets at liquid/solid interfaces and the interfacial ordering is critical to understanding solidification, liquid-phase epitaxial growth, wetting, liquid-phase joining, crystal growth, and lubrication process, all of which are linked to different important applications in material science. In this work, we observe direct in-situ atomic-scale behaviour of Bi droplets segregated on SrBi2Ta2O9 by using aberration corrected transmission electron microscopy and demonstrate ordered interface and surface structures for the droplets on the oxide at the atomic-scale and unravel a nucleation mechanism involving droplet coalescence at the liquid/solid interface. We identify a critical diameter of the formed nanocrystal in stabilizing the crystalline phase and reveal lattice induced fast crystallization of the droplet at the initial stage of the coalescence of nanocrystal with droplet. Further sequential observations show the stepped coalescence and growth mechanism of the nanocrystals at the atomic-scale. These results offer insights into the dynamic process at liquid/solid interfaces, which may have implications for many functionalities of materials and their applications.

Direct Atomic-Scale Observation of Intermediate Pathways of Melting and Crystallization in Supported Bi-Nanoparticles

JPCL_picture

Uncovering the evolutional pathways of melting and crystallization atomically is critical to understanding complex microscopic mechanism of first-order phase transformation. Here, we conduct in-situ atomic-scale observations of melting and crystallization in supported Bi-nanoparticles under heating and cooling within an aberration-corrected TEM. We provide direct evidence to the multiple intermediate state events in melting and crystallization. The melting of the supported nanocrystal involves the formation and migration of domain boundaries and dislocations due to the atomic rearrangement under heating, which occurs through a size-dependent multiple intermediate state. A critical size, which is key to inducing the transition pathway in melting from two to four barriers, is identified for the nanocrystal. In contrast, crystallization of a Bi droplet involves three stages. These findings demonstrate that the phase transformations cannot be viewed as a simple single barrier-crossing event but as a complex multiple intermediate state phenomenon, highlighting the importance of nonlocal behaviors.

In situ Atomic-Scale Study of Particle Mediated Nucleation and Growth in Amorphous Bi to Nanocrystal Phase Transformation

AdvSci_picture

Understanding classical and non-classical mechanisms of crystal nucleation and growth at the atomic scale has been of great interest to scientists in many disciplines. However, fulfilling direct atomic-scale observation still poses a significant challenge. Here, by taking a thin amorphous Bi metal nanosheet as a model system, we provide direct atomic resolution of the crystal nucleation and growth initiated from an amorphous state of Bi metal under electron beam inside an aberration corrected transmission electron microscope. We show that the crystal nucleation and growth in the phase transformation of Bi metal from amorphous to crystalline structure takes place via the particle-mediated non-classical mechanism instead of the classical atom-mediated mechanism. The dimension of the smaller particles in two contacted nanoparticles and their mutual orientation relationship are critical to governing several coalescence pathways: total rearrangement pathway, grain boundary migration dominated pathway and surface migration dominated pathway. Sequential strain analyses imply that migration of grain boundary is driven by strain difference in two Bi nanocrystals and the coalescence of nanocrystals is a defect reduction process. The findings may provide useful information on clarifying nanocrystal growth mechanisms of other materials at the atomic scale.

External Collaborations:

Dr. Qiang Li (School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China).

C. Chen, Dr. H. Wang, and Prof. L. Guo (School of Chemistry and Environment, Beihang University Beijing 100191, China).

Prof. N. Chen (School of Materials Science and Engineering Tsinghua University Beijing 100084, China).

Dr. Zhongchang Wang (Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan).

Publications

  • In situ Atomic-Scale Study of Particle-Mediated Nucleation and Growth in Amorphous Bi to Nanocrystal Phase Transformation, Junjie Li, Jiangchun Chen, Hua Wang, Na Chen, Zhongchang Wang, Lin Guo and Francis Leonard Deepak, Adv. Sci., 2018, 1700992; DOI: 10.1002/advs.201700992.
  • Direct Atomic-Scale Observation of Intermediate Pathways of Melting and  Crystallization in Supported Bi-Nanoparticles, Junjie Li, Zhongchang Wang and Francis Leonard Deepak, J. Phys. Chem. Lett., 2018, 9, 961-969.
  • In Situ Atomic-Scale Observation of Droplet Coalescence Driven Nucleation and Growth at Liquid/Solid Interfaces, Junjie Li, Zhongchang Wang, and Francis Leonard Deepak, ACS Nano, 2017, 11 (6), pp 5590–5597.
  • Real-Time Dynamical Observation of Lattice Induced Nucleation and Growth in Interfacial Solid-Solid Phase Transitions, Junjie Li, Qiang Li, Zhongchang Wang, and Francis Leonard Deepak, Cryst. Growth Des., 2016, 16, 7256−7262.

Nanotubes with Encapsulated Materials

People in this Project: E.A. Anumol and Francis Leonard Deepak

The hollow interior core of nanotubes, both carbon and non-carbon (BN, WS2 etc.) provide the necessary space for the filling, encapsulation and confinement of molecules and crystals both organic and inorganic. In addition they provide templates for the formation of core-shell nanotubes. The reduced dimensionality of the encapsulated material as a consequence of “confinement” presents the advantage of different characteristics compared to that of the bulk material. The interaction between the encapsulated material and the host nanotube plays a crucial role and therefore can govern the structure and electronic properties of such a system.
In this project nanotubes (CNTs as well as Inorganic NTs) which provide accessible space for templated growth of nanotubes or nanorods within them are employed to encapsulate metal halides such as GdI3 and BiI3 which are contrast agents for biomedical imaging. Capillary filling is employed to encapsulate these metal halides within nanotubes of carbon and WS2 to obtain core-shell nanotubes and/or nanorods. Aberration Corrected Scanning/Transmission Electron Microscopy and Spectroscopy using the Titan G2 80-200 TEM/STEM with ChemiSTEM Technology and FEI Titan Themis 60-300 kV is employed to characterize the atomic structure, morphology and composition of these core-shell structures.

Project2_pictureExternal Collaborations
Dr. Pedro Costa and Mr. Nitin M. Batra (KAUST, Saudi Arabia)

Dr. Andrey Enyashin: Molecular Dynamics Simulation (Ural Federal University, Institute of Natural Sciences and Mathematics, Ekaterinburg, Russian Federation).

Publications

(1) Nitin M. Batra, E. A. Anumol, Jasmin Smajic, Andrey N. Enyashin, Francis Leonard Deepak and Pedro M. F. J. Costa, Morphological phase diagram of a metal halide encapsulated in carbon nanotubes, Submitted 2018.

(2) Capillary Imbibition of Gadolinium Halides into WS2 Nanotubes: A Molecular Dynamics, Francis Leonard Deepak and A. N. Enyashin, Isr. J. Chem, Special Issue: Computational Science of Inorganic Nanostructures, 2017, 57, 501-508.

(3) Structural and chemical analysis of gadolinium halides encapsulated within WS2 nanotubes, E. A. Anumol, A. N. Enyashin, N. M. Batra, P. M. F. J. Costa and Francis Leonard Deepak, Nanoscale, 2016, 8, 12170-12181.

3D Tomography and Tomography-Spectroscopy of Nanomaterials

People in this Project: E.A. Anumol and Francis Leonard Deepak

In this project HAADF-STEM tomography is employed to obtain the 3D morphology of nanomaterials such as nanocatalysts and core-shell nanotubes. A Titan G2 80-200 TEM/STEM with ChemiSTEM Technology is used for this. EDX-STEM tomography is employed to obtain 3D chemical mapping. Low accelerating voltage (80 kV) enables tomography of beam sensitive materials such as carbon nanotubes. A high tilt tomography holder  and Super-X EDS detector (in the Titan ChemiSTEM) comprising four SDD detectors enable the EDX mapping in a wide tilt range (-70° to +70°) . Inspect 3D software is used for reconstruction and Amira for visualization.

Project3_pictureExternal Collaborations

Dr. Pedro Costa and Mr. Nitin M. Batra (KAUST, Saudi Arabia)

Dr. Andrey Enyashin – Molecular Dynamics Simulation (Institute of Solid State Chemistry UB RAS Ekaterinburg, RUSSIAN FEDERATION).

Dr. C.P.VinodCSIR-National Chemical Laboratory, India

Publications

(1) Structural and chemical analysis of gadolinium halides encapsulated within WS2 nanotubes, E. A. Anumol, A. N. Enyashin, N. M. Batra, P. M. F. J. Costa and Francis Leonard Deepak, Nanoscale, 2016, 8, 12170-12181.

(2) A Convenient Route for Au@Ti-SiO2 Nanocatalyst Synthesis and its Application for Room Temperature CO Oxidation, A. Yogitha Soni, E. A. Anumol, Chandrani Nayak Francis Leonard Deepak, C. P. Vinod, Chathakudath, Phys. Chem. C 2017, 129, 4946-4957.

Metal Nanoparticles and Clusters

People in this Project: Markus Snellman, Irene Bechis, Joao Freitas, E.A. Anumol, Junjie Li and Francis Leonard Deepak

NJC.jpg

Monometallic, Bimetallic and multimetallic core-shell nanoparticle/nanowire catalysts of noble metal alloys possesses superior activity, high selectivity and stability at low temperature compared to traditional bulk metals. This makes them ideal candidates for carrying out investigations on their structure, nature of alloy formation and thus understand the way the catalytic activity is enhanced. Direct microscopic studies of various bimetallic nanoparticles have been carried out using high-resolution transmission electron microscopy (HRTEM). However, this method is limited because of the small difference in the lattice constant involved. Conventional transmission electron microscopy (CTEM) can produce chemical contrast due to due to different electron beam extinction distances. This has been applied successfully to image bimetallic nanoparticles down to 10 nm in diameter. Since the particles need to be in a low index zone orientation, this method is not easy to use in practice. As an alternative method of nanostructure determination high angle angular dark field (HAADF) imaging technique has been used successfully. The HAADF method has been used to detect variation in chemical composition down to single atom level in structures of nanosized particles. STEM-HAADF imaging carried out in an aberration corrected microscope reveals the atomistic structure and the alloying of bimetallic nanoparticles and nanowires. In combination with high resolution spectral and chemical analysis this techniques provides unprecedented information never obtained till date. Understanding the nature and structure of such bimetallic/multimetallic nanocatalysts is important to enable modification of their structure/morphology/composition and enhance their catalytic performance for fuel cells and other industrial applications.

External Collaborations

Prof. M. Arturo López-Quintela (Dept. Physical Chemistry, Faculty of Chemistry Lab of Nanotechnology and Magnetism (NANOMAG) Research Technological Institute University of Santiago de Compostela)

Dr. P. John Thomas (School of Chemistry, Bangor University, Bangor, UK)

Prof. Maurizio Muniz-Miranda (“Ugo Schiff” Chemistry Dept, University of Florence)

Dr. Roberto Pilot (Consorzio INSTM and Department of Chemical Sciences, via Marzolo 1, 35131 Padova, Italy)

Dr. C.P. Vinod (Catalysis Division and Center of Excellence on Surface Science, CSIR National Chemical Laboratory, Pune, INDIA)

Dr. R. Nandini Devi (Catalysis Division, National Chemical Laboratory, Pune, India)

Dr. Qiang Li (School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China)

Dr. Deqiang Yin (School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China and Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan)

T. Del Rosso, Department of Physics, Pontifi­cia Universidade Catolica do Rio de Janeiro, Brazil

Book Chapters

  • Advanced Electron Microscopy Techniques Towards the Understanding of Metal Nanoparticles and Clusters, Francis Leonard Deepak, E.A. Anumol, Junjie Li, Book: Metal Nanoparticles and Clusters: Recent Advances in the synthesis, properties and applications (Springer), Ed: Francis Leonard Deepak (2018).
  • Advanced Methods of Electron Microscopy in Catalysis Research, Miguel Jose-Yacaman, Arturo Ponce-Pedraza, Sergio Mejia-Rosales and Francis Leonard Deepak, Advances in Imaging & Electron Physics (Academic Press), Editor: Peter Hawkes, vol. 177, pp: 279-342 (2013).

Edited Book

BookCover

Metal Nanoparticles and Clusters Advances in Synthesis, Properties and Applications, Ed: Francis Leonard Deepak, Springer 2018.

Publications

(1) Biocompatible Au@Carbynoid/Pluronic-F127 nanocomposites synthesized by pulsed laser ablation assisted CO2 recycling, T. Del Rosso, S.R.W. Louro, F.L. Deepak, E.C. Romani, Q. Zaman, Tahir, O. Pandoli, M. Cremona, F.L. Freire Junior, P. De Buele, T. De St. Pierre, R.Q. Aucelio, G. Mariotto, S. Gemini- Piperni, A.R. Ribeiro, S.M. Landi, A. Magalhaes, Appl. Surf. Sci., 2018, 441, 347-355.

(2) Qiang Li, Deqiang, Yin, Junjie Li, and Francis Leonard Deepak, Atomic-Scale Understanding of Gold Cluster Growth on Different Substrates and Adsorption-Induced Structural Change, J. Phys. Chem. C 2018, 122, 1753-1760.

(3) Magnetic Nanoparticles obtained by two-step Laser Ablation of Nickel and Silver in pure Water, Cristina Gellini, Francis Leonard Deepak, Maurizio Muniz-Miranda, Stefano Caporali, Francesco Muniz-Miranda, Alfonso Pedone, Claudia Innocenti, Claudio Sangregorio, J. Phys. Chem. C 2017, 121, 3597-3606.

(4) A convenient route for Au@Ti-SiO2 nanocatalyst synthesis and its application for room temperature CO oxidation, Yogita Sonia, A. Anumol, Chandrani Nayak, Francis Leonard Deepak, C.P. Vinod, J. Phys. Chem. C 2017, 129, 4946-4957.

(5) Understanding alloy structure and composition in sinter-resistant AgPd@SiO2 encapsulated catalysts and their effect on catalytic properties, Sourik Mondal, Thattarathody Rajesh, Basab B. Dhar, Markus Snellman, Junjie Li, Francis Leonard Deepak and R. Nandini Devi, New J. Chem., 2017, 41, 14652.

(6) Controlling Bimetallic Nanostructures by the Microemulsion Method with Subnanometer Resolution Using a Prediction Model, David Buceta, Concha Tojo, Miomir Vukmirovic, Francis Leonard Deepak, Arturo M. Lopez-Quintela, Langmuir, 2015, 31, 7435-7439.

(7) Wavelength dispersion of the local field intensity in silver–gold nanocages, R. Pilot, Zoppi, S. Trigari, F. L. Deepak, E. Giorgetti and R. Bozio, Phys. Chem. Chem. Phys., 2015, 17, 7355.

(8) Stable Ruthenium colloids by Laser Ablation, Brandi, S. Caporali, S. Cicchi, L. Lascialfari, M. Muniz-Miranda, S. Orazzini, M. Severi, Francis Leonard Deepak and E. Giorgetti, IEEE NANO, July 2015.

Atomic scale structural characterization of 2D nanomaterials

People in this Project: Junjie Li and Francis Leonard Deepak

Doping is an effective method to tune the electronic properties for MoS2 as well as other 2D semiconductors and has significant implications on their optical and electronic properties. In this project we fabricate doped MoS2 samples with different dopants and/or doping concentrations and study them employing high resolution imaging and spectroscopy.

External Collaborations:

Dr. G. Deokar (University of Namur, Belgium)

Publications

  • G. Deokar, J. J. Li, F. L. Deepak, W. Ou-Yang, N. Reckinger, C. Bittencourt, J.-F. Colomer, M. Jouaid, Field emission properties of vertically aligned MoS2 NSs, Submitted, 2017.

Electron Microscopy and Spectroscopy Study of Modified Titanate Nanotubes (TNTs)

People in this Project: Sharath Kumar and Francis Leonard Deepak

Project6_pictureThe study is aimed at employing electron microcopy in combination with spectroscopic techniques to study these materials and provide an accurate and in-depth understanding into the various aspects related to their catalytic activity. The samples under consideration are transition metal modified TNTs which are prepared by cation exchange of the hydrothermally synthesized TNTs as well as doped TNTs. The techniques include employing Aberration Corrected Electron Microscopy (AC-TEM/STEM) along with the associated spectroscopic techniques, Electron Energy Loss Spectroscopy (EELS) and Energy Dispersive X-Ray Spectroscopy (EDX), as this could provide the structure, composition and morphology of the specimen in a single experiment, from the same region, with high spatial resolution. Of particular importance would be the identification of the cations that are incorporated as dopants (and/or intercalated) and imaging them with single-atom sensitivity, along with elucidation of their oxidation/bonding states of undoped and doped samples (Ti4+ vs Co2+). It is expected that such a detailed experimental study using electron microscopy would provide new insights into the structural and compositional aspects which influences the catalytic properties.

External Collaborations:

Dr. Anabela Rolo (Dept. Physics, U. Minho, Braga, Portugal)

HIGHLIGHTS

July 2018: Sharath successfully completed his Masters Thesis Defense (Thesis Title: Electron Microscopy and Spectroscopy Study of Modified Titanate Nanowires and Nanotubes)

July 2018: FCT Funded Project: Correlated Analysis of Inorganic Solar Cells in and outside an Electron Microscope (CASOLEM) (http://inl.int/funded-projects/) has started.

July 2018: Leonard gave an Invited Talk in ANM-2018 (http://www.advanced-nanomaterials-conference.com/speakers/)

July 2018: Paper Published in Advanced Science

In situ Atomic-Scale Study of Particle-Mediated Nucleation and Growth in Amorphous Bi to Nanocrystal Phase Transformation, Junjie Li, Jiangchun Chen, Hua Wang, Na Chen, Zhongchang Wang, Lin Guo and Francis Leonard Deepak, Adv. Sci., 2018, 1700992; DOI: 10.1002/advs.201700992.

June 2018: Junjie Li presented his work in SCANDEM-2018(http://www.cen.dtu.dk/english/scandem-2018/)

June 2018: Paper published in J.Man.Process

Multilevel Process on Large Area Wafers for Nanoscale Devices, B. J. Pires, A. V. Silva, A. Moskaltsova, F. L. Deepak, P. Brogueira, D. C. Leitao, S. Cardoso, J. Manufacturing Processes, 2018, 32, 222-229.

May 2018: Best Poster Award – First Prize (Workshop on Electron Microscopy May 4th 2018, INL)

Poster: Single Walled BiI3 and GdI3 Nanotubes Encapsulated within CNT, A. Anumol, Nitin M. Batra, Pedro M. F. J. Costa, Andrey N. Enyashin and Francis Leonard Deepak

April 2018: Paper published in Appl.Surf.Sci

Biocompatible Au@Carbynoid/Pluronic-F127 nanocomposites synthesized by pulsed laser ablation assisted CO2 recycling, T. Del Rosso, S.R.W. Louro, F.L.  Deepak, et al. Appl Surf. Sci., 2018, 441, 347-355.

March 2018: Paper published in J. Phys. Chem. Lett

Direct Atomic-Scale Observation of Intermediate Pathways of Melting and Crystallization in Supported Bi-Nanoparticles, Junjie Li, Zhongchang Wang and Francis Leonard Deepak, J. Phys. Chem. Lett., 2018, 9, 961-969.

February 2018: Paper published in J. Phys. Chem. C

Atomic-Scale Understanding of Gold Cluster Growth on Different Substrates and Adsorption-Induced Structural Change, Qiang Li, Deqiang, Yin, Junjie Li, and Francis Leonard Deepak, J. Phys. Chem. C, 2018, 122, 1753-1760.

January 2018: New Book Published by Springer

BookCover

ONGOING NATIONAL AND EUROPEAN PROJECTS

  • N2020: Nanotechnology based functional solutions (NORTE-45-2015-02). Duration: 2016-2018

Previous National and European Projects

  • Regulatory testing of nanomaterials (NANoREG), FP7 Nanotechnologies & Nanosciences Thematic Cooperation Programme, Participant, Duration: 2013-2017.
  • WATERNANOENV (National Project), Axencia Galega de Innovacion  (GAIN)-ERDF Partners: Instituto Tecnologico de Galicia (ITG)-coordinator, Universidade de Santiago de Compostela (USC)-subcontracted and INL-subcontracted, Duration: 2015-2017.
  • NANO-HVAC: Novel Nano-enabled Energy Efficient and Safe HVAC ducts and systems contributing to an healthier indoor environment,  FP7 – Seventh Framework Programme, Duration: 2012-2015.
  • ON2-ERDF: Project Title – Self-assembled functionalized nanomaterials for biomolecular recognition, Call: SAESCTN-PIIC&DT/1/2011, Duration: 2013-2015.

NATIONAL AND INTERNATIONAL COLLABORATIONS

  • University of Minho (Portugal)
  • CICECO – University of Aveiro (Portugal)
  • INESC-MN (Portugal)
  • USC – University of Santiago de Compostela (Spain)
  • University of Florence (Italy)
  • KAUST (Saudi Arabia)
  • University of Bangor(U.K.)
  • NCL Pune (India)
  • Ural Federal University (Russian Federation)
  • UT-Austin (USA)
  • Weizmann Institute of Science (Israel)

PUBLICATIONS

2017

Nitin M. Batra E. A. Anumol, Jasmin Smajic Andrey Enyashin Francis Leonard Deepak; Costa, Pedro

Morphological phase diagram of a metal halide encapsulated in carbon nanotubes (Journal Article)

Submitted, 2017.

(BibTeX)

Yogita Sonia E.A. Anumol, Chandrani Nayak Francis Leonard Deepak Vinod Phys

A convenient route for Au@Ti-SiO2 nanocatalyst synthesis and its application for room temperature CO oxidation (Journal Article)

Chem. C , 129 (4946-4957), 2017.

(BibTeX)

Sourik Mondal Thattarathody Rajesh, Basab Dhar Markus Snellman Junjie Li Francis Leonard Deepak Nandini Devi

Understanding alloy structure and composition in sinter-resistant AgPd@SiO2 encapsulated catalysts and their effect on catalytic properties (Journal Article)

Submitted , 2017.

(BibTeX)

Cristina Gellini Francis Leonard Deepak, Maurizio Muniz Miranda Stefano Caporali Francesco Muniz-Miranda Alfonso Pedone Claudia Innocenti; Claudio Sangregorio, Phys

Magneto-Plasmonic Colloidal Nanoparticles Obtained by Laser Ablation of Nickel and Silver Targets in Water (Journal Article)

Chem. C, (121), pp. 3597−3606, 2017.

(BibTeX)

Junjie Li Zhongchang Wang, Francis Leonard Deepak

In-situ Atomic-scale Observation of Droplets Coalescence Driven Nucleation and Growth at Liquid/Solid Interface (Journal Article)

Submitted, 2017.

(BibTeX)

2016

E. A. Anumol A. N. Enyashin, Batra Costa; Deepak, Francis Leonard

Structural and chemical analysis of gadolinium halides encapsulated within WS2 nanotubes (Journal Article)

Nanoscale, (8), pp. 12170-12181, 2016.

(BibTeX)

Deepak, Francis Leonard; Enyashin,

Capillary Imbibition of Gadolinium Halides into WS2 Nanotubes: A Molecular Dynamics View (Journal Article)

Isr. J. Chem., 2016.

(Links | BibTeX)

Junjie Li Qiang Li, Zhongchang Wang; Deepak, Francis Leonard

Real-Time Dynamical Observation of Lattice Induced Nucleation and Growth in Interfacial Solid-Solid Phase Transitions (Journal Article)

Cryst. Growth Des., Just Accepted Manuscript, 2016.

(Links | BibTeX)

J. Rodrigo Magana Yury V. Kolen’ko, Francis Leonard Deepak Conxita Solans Rekha Goswami Shrestha Jonathan Hill Katsuhiko Ariga Lok Kumar Shrestha; Rodriguez-Abreu, Carlos

From Chromonic Self-Assembly to Hollow Carbon Nanofibers for Efficient Materials in Supercapacitor and Vapor Sensing Applications (Journal Article)

ACS Applied Materials & Interfaces, 2016.

(Links | BibTeX)

2015

Francis Leonard Deepak Manuel Bañobre-López, Enrique Carbó-Argibay Fátima Cerqueira Yolanda Piñeiro-Redondo JoséRivas Corey Thompson Saeed Kamali Carlos Rodríguez-Abreu Kirill Kovnir; Kolenko, Yury

A Systematic Study of the Structural and Magnetic Properties of Mn‑, Co‑, and Ni-Doped Colloidal Magnetite Nanoparticles (Journal Article)

J. Phys. Chem C, (119), pp. 11947-11957, 2015.

(BibTeX)

David Buceta Concha Tojo, Miomir Vukmirovic Francis Leonard Deepak Arturo Lopez-Quintela

Controlling Bimetallic Nanostructures by the Microemulsion Method with Subnanometer Resolution Using a Prediction Model (Journal Article)

Langmuir, (31), pp. 7435-7439, 2015.

(BibTeX)

Eunice Cunha M. Fernanda Proença, Florinda Costa António Fernandes Marta Ferro Paulo Lopes Mariam Debs Manuel Melle-Franco Francis Leonard Deepak Maria Paiva

Self-assembled functionalized graphene nanoribbons from carbon nanotubes (Journal Article)

ChemistryOpen, (4), pp. 115 – 119, 2015.

(BibTeX)

Maryam Salimian Maxim Ivanov, Francis Leonard Deepak Dmitri Petrovykh Igor Bdikin Marta Ferro Andre Kholkin Elby Titus; Goncalves, Gil

Synthesis and characterization of reduced graphene oxide /spiky nickel nanocomposites for nanoelectronic applications (Journal Article)

J. Mater. Chem. C, (3), pp. 11516 – 11523, 2015.

(BibTeX)

R. Pilot A. Zoppi, Trigari Deepak Giorgettib; Bozioa,

Wavelength dispersion of the local field intensity in silver–gold nanocages (Journal Article)

Phys.Chem.Chem.Phys., (17), pp. 7355, 2015.

(BibTeX)

Nitin M Batra Shashikant P Patole, Ahmed Abdelkader Dalaver Anjum Francis Deepak; Costa, Pedro

Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices (Journal Article)

Nanotechnology, (26), pp. 445301, 2015.

(BibTeX)

J. D. Costa S. Serrano-Guisan, Borme Deepak Tarequzzaman Paz J.Ventura Ferreira; Freitas,

Impact of MgO thickness on the performance of Spin Transfer Torque Nano-Oscillators​ (Journal Article)

IEEE Trans. Magn, (52), pp. 1401604, 2015.

(BibTeX)

2014

Francis Leonard Deepak Jose Rivas, Miguel Jose-Yacaman

Understanding the structure of nanocatalysts with High Resolution Scanning/ Transmission Electron Microscopy (Journal Article)

IOP Conf. Ser.: Mater. Sci. Eng, (55), pp. 012005 , 2014.

(BibTeX)

Stephanie Vial Dmytro Nykypanchuk, Francis Leonard Deepak Marta Prado; Gan, Oleg

Plasmonic response of DNA-Assembled Gold Nanorods (AuNRs) (Journal Article)

Journal of Colloid and Interface Science, (433), pp. 34-42, 2014.

(BibTeX)

Yury V. Kolen’ko Manuel Bañobre-López, Carlos Rodríguez-Abreu Enrique Carbó-Argibay Francis Leonard Deepak Dmitri Petrovykh Fátima Cerqueira Saeed Kamali Kirill Kovnir Dmitry Shtansky Oleg Lebedev; Rivas, Jose

High-Temperature Magnetism as a Probe for Structural and Compositional Uniformity in Ligand-Capped Magnetite Nanoparticles (Journal Article)

J. Phys. Chem. C , (118), pp. 28322−28329, 2014.

(BibTeX)

Ana V. Silva Diana C. Leitao, Ricardo Ferreira Elvira Paz Francis Leonard Deepak Susana Cardoso; Freitas, Paulo

Linear nanometric tunnel junction sensors with exchange pinned sensing layer (Journal Article)

Journal of Applied Physics, (115), pp. 17E526, 2014.

(BibTeX)

Diana C. Leitao Elvira Paz, Ana Silva Anastasiia Moskaltsova Simon Knudde Francis Deepak Ricardo Ferreira Susana Cardoso; Freitas, Paulo

Nanoscale Magnetic Tunnel Junction sensing devices with soft pinned sensing layer and low aspect ratio (Journal Article)

IEEE Transactions on Magnetics, 50 , pp. 4410508, 2014.

(BibTeX)

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