Spintronics
- Home
- Nanoelectronics Engineering
- Spintronics
DEPARTMENTS
RESEARCH GROUPS
Latest Publications
- Excitation and coherent control of magnetization dynamics in magnetic tunnel junctions using acoustic pulsesIn: Applied Physics Letters, 113 (7), pp. 072403, 2018.H. F. Yang, F. Garcia-Sanchez, X. K. Hu, S. Sievers, T. Böhnert, J. D. Costa, M. Tarequzzaman, R. Ferreira, M. Bieler, H. W. Schumacher
- Broadband voltage rectifier induced by linear bias dependence in CoFeB/MgO magnetic tunnel junctionsIn: Applied Physics Letters, 112 (25), pp. 252401, 2018, (arXiv: 1804.04104).M. Tarequzzaman, A. S. Jenkins, T. Böhnert, J. Borme, L. Martins, E. Paz, R. Ferreira, P. P. Freitas
- Magnetic tunnel junction thermocouple for thermoelectric power harvestingIn: Physics Letters A, 2018, ISSN: 0375-9601.T. Böhnert, E. Paz, R. Ferreira, P.P. Freitas
DESCRIPTION
Spintronics is a research area trying to take profit from the spin of the electrons as a mean to obtain, transmit and process information. The spin of the electrons is a degree of freedom that is not explored by conventional electronics rely only on the electrical charge to drive electronic circuits. Spintronics use magnetic materials patterned at the nano-scale to produce spin polatized currents which drive a new class of beyond CMOS components which include magnetic field sensors, non-volatile memories and RF devices.
A full wafer of MTJs with heater line and temperature sensors for spin-caloric measurements.
Cross section of an MTJ nanopillar (FIB-Lamella).
Two MTJ nanopillars in an intermediate fabrication step. Both have a diameter far below 100 nm.
TOPICS
MAGLINE
Project Time Frame: Apr 2017 to Jan 2020
MAGLINE: Desenvolvimento e Validação Industrial do Processo de Fabricação de Sensores TMR
The latest generation of sensors (TMR) has major advantages over previous (Hall and GMR), and there is a market with sustained growth for application of these sensors. However the lack of industrial production capacity prevents its adoption in large scale commercial applications, although it is possible to acquire them commercially those marketed generic sensors are not optimized for any particular application. There is a clear opportunity to capture this market, and provide the market a large-scale production solution TMR sensors optimized and custom-made for different applications.
PRODUTECH-SIF
Project Time Frame: Nov 2017 to Sep 2020
The project embodies a comprehensive response towards the development and implementation of new production systems, embedding advanced production technologies that will equip the manufacturing industry to meet the challenges and opportunities of the 4th industrial revolution.
INFANTE
Project Time Frame: Nov 2017 to Sep 2020
INFANTE is a development and demonstration project for an in-orbit microsatellite, to be launched in 2020. This is the precursor of a constellation for Earth observation and communication with the focus on maritime applications.
INFANTE will be the first satellite developed by the Portuguese Industry, articulated in a national consortium led by TEKEVER group, that includes 9 companies with references in the space sector, as Active Space Technologies, Omnidea, Active Aerogels, GMV, HPS and Spinworks; and 10 internationally recognized R&D Centers in their areas of competence, such as CEIIA; FEUP, ISQ, FCT-UNL, INL, IPN, IPTomar, ISR Lisbon, IT Aveiro, and UBI.
MOSAIC
Project Time Frame: Jan 2013 to Sep 2016
The broader objective is to bring the device level knowledge acquired in the past years by the partners towards systems as a first crucial step towards industrialization, warranting the leading position not only of European research but also of European industry in microwave spintronics.
SPINICUR webpage
Project Time Frame: Oct. 2012- Mar. 2016
SPINICUR (from spin currents) is a training network of European experts dedicated to providing state-of-the-art education and training for early stage and experienced researchers. We have concentrated on an aspect of spintronics – pure spin currents – and specific technical goals in order to secure a very high level of industrial involvement and strong network connectivity through a sharp focus.
SpinCal webpage
Project Time Frame: Jul. 2013 – Jun. 2016
SpinCal stands for Spintronics and spin-caloritronics in magnetic nanosystems, a joint research project (JRP) funded by the European Metrology Research Programme (EMRP). The aim of the project is to enable fundamental understanding of new effects emerging in the field of spintronics and spin-caloritronics in magnetic nanosystems. This goal was achieved by developing a new measurement infrastructure and a best practice guide for spin-caloritronic material measurements, providing a road map towards future standardisation of spintronic and spin-caloritronic measurements, materials and devices.
INTEGRATION
Project Time Frame: 2012-2015
Towards hybrid integrated heterogeneous technology devices.
PERPENDICULAR (PTDC-CTM-MET-118236-2010)
Project Time Frame: Jul. 2012- Jun. 2014
Advanced MRAM Structures using Perpendicular Magnetization Materials for Spin Transfer Writing.
PUBLICATIONS
-
2018
Yang, H F; Garcia-Sanchez, F; Hu, X K; Sievers, S; Böhnert, T; Costa, J D; Tarequzzaman, M; Ferreira, R; Bieler, M; Schumacher, H W
Excitation and coherent control of magnetization dynamics in magnetic tunnel junctions using acoustic pulses Journal Article
Applied Physics Letters, 113 (7), pp. 072403, 2018.
@article{Yang2018,
title = {Excitation and coherent control of magnetization dynamics in magnetic tunnel junctions using acoustic pulses},
author = {H. F. Yang and F. Garcia-Sanchez and X. K. Hu and S. Sievers and T. Böhnert and J. D. Costa and M. Tarequzzaman and R. Ferreira and M. Bieler and H. W. Schumacher},
url = {https://doi.org/10.1063/1.5037780},
doi = {10.1063/1.5037780},
year = {2018},
date = {2018-08-01},
journal = {Applied Physics Letters},
volume = {113},
number = {7},
pages = {072403},
publisher = {AIP Publishing},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Tarequzzaman, M; Jenkins, A S; Böhnert, T; Borme, J; Martins, L; E. Paz, Ferreira R; Freitas, P P
Broadband voltage rectifier induced by linear bias dependence in CoFeB/MgO magnetic tunnel junctions Journal Article
Applied Physics Letters, 112 (25), pp. 252401, 2018, (arXiv: 1804.04104).
@article{Tarequzzaman2018ab,
title = {Broadband voltage rectifier induced by linear bias dependence in CoFeB/MgO magnetic tunnel junctions},
author = {M. Tarequzzaman and A. S. Jenkins and T. Böhnert and J. Borme and L. Martins and E. Paz, R. Ferreira and P. P. Freitas},
url = {https://doi.org/10.1063/1.5029363},
doi = {10.1063/1.5029363},
year = {2018},
date = {2018-06-01},
urldate = {2018-04-13},
journal = {Applied Physics Letters},
volume = {112},
number = {25},
pages = {252401},
abstract = {In this paper, the perpendicular magnetic anisotropy (PMA) is tailored by changing the thickness of the free layer with the objective of producing MTJ nano-pillars with smooth linear resistance dependence with both in-plane magnetic field and DC bias. We furthermore demonstrate how this linear bias dependence can be used to create a zero-threshold broadband voltage rectifier, a feature which is important for rectification in wireless charging and energy harvesting applications. By carefully balancing the amount of PMA acting in the free layer the measured RF to DC voltage conversion efficiency can be made as large as 11%.},
note = {arXiv: 1804.04104},
keywords = {},
pubstate = {published},
tppubtype = {article}
}In this paper, the perpendicular magnetic anisotropy (PMA) is tailored by changing the thickness of the free layer with the objective of producing MTJ nano-pillars with smooth linear resistance dependence with both in-plane magnetic field and DC bias. We furthermore demonstrate how this linear bias dependence can be used to create a zero-threshold broadband voltage rectifier, a feature which is important for rectification in wireless charging and energy harvesting applications. By carefully balancing the amount of PMA acting in the free layer the measured RF to DC voltage conversion efficiency can be made as large as 11%.Böhnert, T; Paz, E; Ferreira, R; Freitas, P P
Magnetic tunnel junction thermocouple for thermoelectric power harvesting Journal Article
Physics Letters A, 2018, ISSN: 0375-9601.
@article{Boehnert2018,
title = {Magnetic tunnel junction thermocouple for thermoelectric power harvesting},
author = {T. Böhnert and E. Paz and R. Ferreira and P.P. Freitas},
url = {https://www.sciencedirect.com/science/article/pii/S0375960118302032},
doi = {10.1016/j.physleta.2018.02.029},
issn = {0375-9601},
year = {2018},
date = {2018-03-01},
journal = {Physics Letters A},
publisher = {Elsevier BV},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Merazzo, K J; Costa, T; Franco, F; Ferreira, R; Zander, M; Türr, M; Becker, T; Freitas, P P; Cardoso, S
Reading magnetic ink patterns with magnetoresistive sensors Journal Article
AIP Advances, 8 (5), pp. 056633, 2018.
@article{Merazzo2018,
title = {Reading magnetic ink patterns with magnetoresistive sensors},
author = {K. J. Merazzo and T. Costa and F. Franco and R. Ferreira and M. Zander and M. Türr and T. Becker and P. P. Freitas and S. Cardoso},
url = {https://aip.scitation.org/doi/full/10.1063/1.5007693},
doi = {10.1063/1.5007693},
year = {2018},
date = {2018-01-01},
journal = {AIP Advances},
volume = {8},
number = {5},
pages = {056633},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Tarequzzaman, M; Böhnert, T; Decker, M; Costa, J D; Borme, J; Lacoste, B; Paz, E; Jenkins, A S; Serrano-Guisan, S; Back, C H; Ferreira, R; Freitas, P P
2018, visited: 10.04.2018, (arXiv: 1802.02224).
@online{Tarequzzaman2018a,
title = {Magnetic oscillations Excited by Concurrent Spin Injection from a Tunneling Current and a Spin Hall Current},
author = { M. Tarequzzaman and T. Böhnert and M. Decker and J. D. Costa and J. Borme and B. Lacoste and E. Paz and A. S. Jenkins and S. Serrano-Guisan and C. H. Back and R. Ferreira and P. P. Freitas},
url = {https://arxiv.org/abs/1802.02224},
year = {2018},
date = {2018-01-01},
urldate = {2018-04-10},
journal = {arXiv:1802.02224 [cond-mat]},
abstract = {In this paper, a 3-terminal spin-transfer torque nano-oscillator (STNO) is studied using the concurrent spin injection of a spin-polarized tunneling current and a spin Hall current exciting the free layer into dynamic regimes beyond what is achieved by each individual mechanism. The pure spin injection is capable of inducing oscillations in the absence of charge currents effectively reducing the critical tunneling current to zero. This reduction of the critical charge currents can improve the endurance of both STNOs and non-volatile magnetic memories (MRAM) devices. It is shown that the system response can be described in terms of an injected spin current density $J_s$ which results from the contribution of both spin injection mechanisms, with the tunneling current polarization $p$ and the spin Hall angle $textbackslashtheta$ acting as key parameters determining the efficiency of each injection mechanism. The experimental data exhibits an excellent agreement with this model which can be used to quantitatively predict the critical points ($J_s = -2.26textbackslashpm 0.09 textbackslashtimes 10textasciicircum9 textbackslashhbar/e$ A/m$textasciicircum2$) and the oscillation amplitude as a function of the input currents. In addition, the fitting of the data also allows an independent confirmation of the values estimated for the spin Hall angle and tunneling current polarization as well as the extraction of the damping $textbackslashalpha = 0.01$ and non-linear damping $Q = 3.8textbackslashpm 0.3$ parameters.},
note = {arXiv: 1802.02224},
keywords = {},
pubstate = {published},
tppubtype = {online}
}In this paper, a 3-terminal spin-transfer torque nano-oscillator (STNO) is studied using the concurrent spin injection of a spin-polarized tunneling current and a spin Hall current exciting the free layer into dynamic regimes beyond what is achieved by each individual mechanism. The pure spin injection is capable of inducing oscillations in the absence of charge currents effectively reducing the critical tunneling current to zero. This reduction of the critical charge currents can improve the endurance of both STNOs and non-volatile magnetic memories (MRAM) devices. It is shown that the system response can be described in terms of an injected spin current density $J_s$ which results from the contribution of both spin injection mechanisms, with the tunneling current polarization $p$ and the spin Hall angle $textbackslashtheta$ acting as key parameters determining the efficiency of each injection mechanism. The experimental data exhibits an excellent agreement with this model which can be used to quantitatively predict the critical points ($J_s = -2.26textbackslashpm 0.09 textbackslashtimes 10textasciicircum9 textbackslashhbar/e$ A/m$textasciicircum2$) and the oscillation amplitude as a function of the input currents. In addition, the fitting of the data also allows an independent confirmation of the values estimated for the spin Hall angle and tunneling current polarization as well as the extraction of the damping $textbackslashalpha = 0.01$ and non-linear damping $Q = 3.8textbackslashpm 0.3$ parameters.Tarequzzaman, M; Bohnert, T; Jenkins, A S; Borme, J; Paz, E; Ferreira, R; Freitas, P P
Influence of MgO Tunnel Barrier Thickness on the Output Power of Three-Terminal Spin Hall Nano-Oscillators Journal Article
IEEE Transactions on Magnetics, pp. 1–4, 2018.
@article{Tarequzzaman2018b,
title = {Influence of MgO Tunnel Barrier Thickness on the Output Power of Three-Terminal Spin Hall Nano-Oscillators},
author = {M. Tarequzzaman and T. Bohnert and A. S. Jenkins and J. Borme and E. Paz and R. Ferreira and P. P. Freitas},
doi = {10.1109/tmag.2018.2831242},
year = {2018},
date = {2018-01-01},
journal = {IEEE Transactions on Magnetics},
pages = {1--4},
publisher = {Institute of Electrical and Electronics Engineers (IEEE)},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Ferreira, Ricardo; Paz, Elvira
Magnetoresistive sensor Patent
US20180180686A1, 2018.
@patent{Ferreira2018,
title = {Magnetoresistive sensor},
author = { Ricardo Ferreira and Elvira Paz},
url = {https://patents.google.com/patent/US20180180686A1/en},
year = {2018},
date = {2018-01-01},
urldate = {2018-08-03},
number = {US20180180686A1},
abstract = {A magnetoresistive sensor is provided. The magnetoresistive sensor comprises a magnetic sensing layer, a magnetic reference layer, and a tunnel barrier layer between the magnetic sensing layer and the magnetic reference layer. The magnetoresistive sensor also comprises a sensing exchange layer having a layer of anti-ferromagnetic material. The sensing exchange layer is exchange coupled with the magnetic sensing layer. Also, the magnetoresistive sensor still further comprises a reference exchange layer having a layer of anti-ferromagnetic material. The reference exchange layer is exchange coupled with the magnetic reference layer. Moreover, the magnetoresistive sensor is configured such that in the absence of an external magnetic field, an exchange bias pinning the reference layer lies along a reference direction, an exchange bias pinning the sensing layer lies along a first direction that is orthogonal to the reference direction, and a magnetic anisotropy of the sensing layer is parallel to the first direction.},
keywords = {},
pubstate = {published},
tppubtype = {patent}
}A magnetoresistive sensor is provided. The magnetoresistive sensor comprises a magnetic sensing layer, a magnetic reference layer, and a tunnel barrier layer between the magnetic sensing layer and the magnetic reference layer. The magnetoresistive sensor also comprises a sensing exchange layer having a layer of anti-ferromagnetic material. The sensing exchange layer is exchange coupled with the magnetic sensing layer. Also, the magnetoresistive sensor still further comprises a reference exchange layer having a layer of anti-ferromagnetic material. The reference exchange layer is exchange coupled with the magnetic reference layer. Moreover, the magnetoresistive sensor is configured such that in the absence of an external magnetic field, an exchange bias pinning the reference layer lies along a reference direction, an exchange bias pinning the sensing layer lies along a first direction that is orthogonal to the reference direction, and a magnetic anisotropy of the sensing layer is parallel to the first direction. -
2017
Silva, Ana V; Ferreira, Ricardo; Paz, Elvira; Leitao, Diana C; Devolder, Thibaut; Cardoso, Susana; Freitas, Paulo P
Thermal FMR Spectral Characterization of Very Low RA In-Plane MgO Magnetic Tunnel Junctions Journal Article
IEEE Transactions on Magnetics, 53 (11), pp. 1–5, 2017.
@article{Silva2017,
title = {Thermal FMR Spectral Characterization of Very Low RA In-Plane MgO Magnetic Tunnel Junctions},
author = {Ana V. Silva and Ricardo Ferreira and Elvira Paz and Diana C. Leitao and Thibaut Devolder and Susana Cardoso and Paulo P. Freitas},
url = {https://ieeexplore.ieee.org/document/7934052/},
doi = {10.1109/tmag.2017.2707798},
year = {2017},
date = {2017-11-01},
journal = {IEEE Transactions on Magnetics},
volume = {53},
number = {11},
pages = {1--5},
publisher = {Institute of Electrical and Electronics Engineers (IEEE)},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Vidal, Enrique García; Muñoz, Diego Ramírez; Arias, Sergio Iván Ravelo; Moreno, Jaime Sánchez; Cardoso, Susana; Ferreira, Ricardo; Freitas, Paulo
Electronic Energy Meter Based on a Tunnel Magnetoresistive Effect (TMR) Current Sensor Journal Article
Materials, 10 (10), pp. 1134, 2017.
@article{Vidal2017,
title = {Electronic Energy Meter Based on a Tunnel Magnetoresistive Effect (TMR) Current Sensor},
author = {Enrique García Vidal and Diego Ramírez Muñoz and Sergio Iván Ravelo Arias and Jaime Sánchez Moreno and Susana Cardoso and Ricardo Ferreira and Paulo Freitas},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5666940/},
doi = {10.3390/ma10101134},
year = {2017},
date = {2017-09-01},
journal = {Materials},
volume = {10},
number = {10},
pages = {1134},
publisher = {MDPI AG},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Costa, J D; Serrano-Guisan, S; Lacoste, B; Jenkins, A S; Böhnert, T; Tarequzzaman, M; Borme, J; Deepak, F L; Paz, E; Ventura, J; Ferreira, R; Freitas, P P
High power and low critical current density spin transfer torque nano-oscillators using MgO barriers with intermediate thickness Journal Article
Scientific Reports, 7 (1), 2017.
@article{Costa2017,
title = {High power and low critical current density spin transfer torque nano-oscillators using MgO barriers with intermediate thickness},
author = {J. D. Costa and S. Serrano-Guisan and B. Lacoste and A. S. Jenkins and T. Böhnert and M. Tarequzzaman and J. Borme and F. L. Deepak and E. Paz and J. Ventura and R. Ferreira and P. P. Freitas},
url = {https://www.nature.com/articles/s41598-017-07762-z},
doi = {10.1038/s41598-017-07762-z},
year = {2017},
date = {2017-08-01},
journal = {Scientific Reports},
volume = {7},
number = {1},
publisher = {Springer Nature},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Böhnert, T; Serrano-Guisan, S; Paz, E; Lacoste, B; Ferreira, R; Freitas, P P
Magnetic tunnel junctions with integrated thermometers for magnetothermopower measurements Journal Article
Journal of Physics: Condensed Matter, 29 (18), pp. 185303, 2017.
@article{Boehnert2017,
title = {Magnetic tunnel junctions with integrated thermometers for magnetothermopower measurements},
author = {T Böhnert and S Serrano-Guisan and E Paz and B Lacoste and R Ferreira and P P Freitas},
url = {https://iopscience.iop.org/article/10.1088/1361-648X/aa63ab},
doi = {10.1088/1361-648x/aa63ab},
year = {2017},
date = {2017-04-01},
journal = {Journal of Physics: Condensed Matter},
volume = {29},
number = {18},
pages = {185303},
publisher = {IOP Publishing},
abstract = {Magnetic tunnel junction (MTJ) micropillars were fabricated with integrated thermometers and a heater line (HL) for thermovoltage measurements. This novel thermometer configuration enabled a direct measurement of ? T across the MTJ micropillar. The MTJ devices were patterned from a CoFeB/MgO/CoFeB stack, with a 1.2?nm to 1.6?nm MgO wedge across the wafer, resulting in resistance area products in the range of 0.7 k? · µ m 2 ?? keywords = {},
pubstate = {published},
tppubtype = {article}
}Magnetic tunnel junction (MTJ) micropillars were fabricated with integrated thermometers and a heater line (HL) for thermovoltage measurements. This novel thermometer configuration enabled a direct measurement of ? T across the MTJ micropillar. The MTJ devices were patterned from a CoFeB/MgO/CoFeB stack, with a 1.2?nm to 1.6?nm MgO wedge across the wafer, resulting in resistance area products in the range of 0.7 k? · µ m 2 ??<?? R ??×?? A ??<??55 k? · µ m 2 . This allowed the measurement of thermoelectric properties as a function of the tunnel barrier thickness. The thermometers showed a homogeneous heating behavior for all devices across the wafer. Combining the in-stack temperature measurements and finite element simulations the thermal profile across the MTJ structure and the thermopower were estimated with a noticeable improvement of the measurement accuracy. The studied MTJ structures showed tunneling magnetoresistance (TMR) ratios up to 125%, and tunneling magnetothermopower (TMTP) up to 35%.Kuepferling, M; Garcia-Sanchez, F; Boehnert, T; Ferreira, R; Dutra, R; Sommer, R L; Pasquale, M
Influence of thermal gradients on the vortex dynamics in CoFeB MTJs Inproceedings
2017 IEEE International Magnetics Conference (INTERMAG), pp. 1-1, 2017.
@inproceedings{Kuepferling2017,
title = {Influence of thermal gradients on the vortex dynamics in CoFeB MTJs},
author = { M. Kuepferling and F. Garcia-Sanchez and T. Boehnert and R. Ferreira and R. Dutra and R. L. Sommer and M. Pasquale},
doi = {10.1109/INTMAG.2017.8007757},
year = {2017},
date = {2017-04-01},
booktitle = {2017 IEEE International Magnetics Conference (INTERMAG)},
pages = {1-1},
abstract = {It was recently shown that the presence of thermal gradients in magnetic nano-devices influences the magnetization state and dynamics in several ways, as for example by the generation of spin currents, spin waves, spin transfer torque, etc..},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}It was recently shown that the presence of thermal gradients in magnetic nano-devices influences the magnetization state and dynamics in several ways, as for example by the generation of spin currents, spin waves, spin transfer torque, etc..Böhnert, Tim ; Dutra, Roberta ; Sommer, Rubem L; Paz, Elvira ; Serrano-Guisan, Santiago ; Ferreira, Ricardo ; Freitas, Paulo P
Influence of the thermal interface resistance on the thermovoltage of a magnetic tunnel junction Journal Article
Physical Review B, 95 , pp. 104441, 2017.
@article{Boehnert2017a,
title = {Influence of the thermal interface resistance on the thermovoltage of a magnetic tunnel junction},
author = {Böhnert, Tim and Dutra, Roberta and Sommer, Rubem L. and Paz, Elvira and Serrano-Guisan, Santiago and Ferreira, Ricardo and Freitas, Paulo P.},
url = {https://link.aps.org/doi/10.1103/PhysRevB.95.104441},
doi = {10.1103/PhysRevB.95.104441},
year = {2017},
date = {2017-03-01},
journal = {Physical Review B},
volume = {95},
pages = {104441},
publisher = {American Physical Society},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Martins, L; Ventura, J; Ferreira, R; Freitas, P P
Optimization of the buffer surface of CoFeB/MgO/CoFeB-based magnetic tunnel junctions by ion beam milling Journal Article
Applied Surface Science, 424 , pp. 58 - 62, 2017, ISSN: 0169-4332, (7th International Conference on Advanced Nanomaterials, 2nd International Conference on Graphene Technology, 1st International Conference on Spintronics Materials).
@article{Martins2017,
title = {Optimization of the buffer surface of CoFeB/MgO/CoFeB-based magnetic tunnel junctions by ion beam milling},
author = {L. Martins and J. Ventura and R. Ferreira and P.P. Freitas},
url = {http://www.sciencedirect.com/science/article/pii/S0169433217304750},
doi = {https://doi.org/10.1016/j.apsusc.2017.02.112},
issn = {0169-4332},
year = {2017},
date = {2017-01-01},
journal = {Applied Surface Science},
volume = {424},
pages = {58 - 62},
abstract = {Due to their high tunnel magnetoresistance (TMR) ratios at room temperature, magnetic tunnel junctions (MTJs) with a crystalline MgO insulating barrier and CoFeB ferromagnetic (FM) layers are the best candidates for novel magnetic memory applications. To overcome impedance matching problems in electronic circuits, the MgO barrier must have an ultra-low thickness (∼1nm). Therefore, it is mandatory to optimize the MTJ fabrication process, in order to prevent relevant defects in the MgO barrier that could affect the magnetic and electrical MTJ properties. Here, a smoothing process aiming to decrease the roughness of the buffer surface before the deposition of the full MTJ stack is proposed. An ion beam milling process was used to etch the surface of an MTJ buffer structure with a Ru top layer. The morphologic results prove an effective decrease of the Ru surface roughness with the etching time. The electrical and magnetic results obtained for MTJs with smoothed buffer structures show a direct influence of the buffer roughness and coupling field on the improvement of the TMR ratio.},
note = {7th International Conference on Advanced Nanomaterials, 2nd International Conference on Graphene Technology, 1st International Conference on Spintronics Materials},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Due to their high tunnel magnetoresistance (TMR) ratios at room temperature, magnetic tunnel junctions (MTJs) with a crystalline MgO insulating barrier and CoFeB ferromagnetic (FM) layers are the best candidates for novel magnetic memory applications. To overcome impedance matching problems in electronic circuits, the MgO barrier must have an ultra-low thickness (∼1nm). Therefore, it is mandatory to optimize the MTJ fabrication process, in order to prevent relevant defects in the MgO barrier that could affect the magnetic and electrical MTJ properties. Here, a smoothing process aiming to decrease the roughness of the buffer surface before the deposition of the full MTJ stack is proposed. An ion beam milling process was used to etch the surface of an MTJ buffer structure with a Ru top layer. The morphologic results prove an effective decrease of the Ru surface roughness with the etching time. The electrical and magnetic results obtained for MTJs with smoothed buffer structures show a direct influence of the buffer roughness and coupling field on the improvement of the TMR ratio.Yang, H F; Hu, X K; Liebing, N; Böhnert, T; Costa, J D; Tarequzzaman, M; Ferreira, R; Sievers, S; Bieler, M; Schumacher, H W
Electrical measurement of absolute temperature and temperature transients in a buried nanostructure under ultrafast optical heating Journal Article
Applied Physics Letters, 110 (23), pp. 232403, 2017.
@article{Yang2017,
title = {Electrical measurement of absolute temperature and temperature transients in a buried nanostructure under ultrafast optical heating},
author = {H. F. Yang and X. K. Hu and N. Liebing and T. Böhnert and J. D. Costa and M. Tarequzzaman and R. Ferreira and S. Sievers and M. Bieler and H. W. Schumacher},
url = {https://aip.scitation.org/doi/full/10.1063/1.4985434},
doi = {10.1063/1.4985434},
year = {2017},
date = {2017-01-01},
journal = {Applied Physics Letters},
volume = {110},
number = {23},
pages = {232403},
keywords = {},
pubstate = {published},
tppubtype = {article}
} -
2016
Huisman, TJ; Mikhaylovskiy, RV; Costa, JD; Freimuth, F; Paz, E; Ventura, J; Freitas, PP; Blügel, S; Mokrousov, Y; Rasing, Th; Kimel, T
Femtosecond control of electric currents in metallic ferromagnetic heterostructures Journal Article
Nature Nanotechnology, 11 , pp. 455, 2016.
@article{Huisman2016,
title = {Femtosecond control of electric currents in metallic ferromagnetic heterostructures},
author = {TJ Huisman and RV Mikhaylovskiy and JD Costa and F Freimuth and E Paz and J Ventura and PP Freitas and S Blügel and Y Mokrousov and Th Rasing and T Kimel},
url = {https://www.nature.com/articles/nnano.2015.331},
doi = {10.1038/nnano.2015.331},
year = {2016},
date = {2016-01-01},
journal = {Nature Nanotechnology},
volume = {11},
pages = {455},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Knudde, S; Farinha, G; Leitao, D C; Ferreira, R; Cardoso, S; Freitas, P P
AlOx barrier growth in magnetic tunnel junctions for sensor applications Journal Article
Journal of Magnetism and Magnetic Materials, 412 , pp. 181-184, 2016.
@article{Knudde2016,
title = {AlOx barrier growth in magnetic tunnel junctions for sensor applications},
author = { S. Knudde and G. Farinha and D. C. Leitao and R. Ferreira and S. Cardoso and P. P. Freitas},
url = {https://www.sciencedirect.com/science/article/pii/S0304885316303110},
doi = {10.1016/j.jmmm.2016.04.008},
year = {2016},
date = {2016-01-01},
journal = {Journal of Magnetism and Magnetic Materials},
volume = {412},
pages = {181-184},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Romera, M; Talatchian, P; Lebrun, R; Merazzo, K J; Bortolotti, P; Vila, L; Costa, J D; Ferreira, R; Freitas, P P; Cyrille, M C; Ebels, U; Cros, V; Grollier, J
Enhancing the injection locking range of spin torque oscillators through mutual coupling Journal Article
Applied Physics Letters, 109 (25), 2016.
@article{Romera2016,
title = {Enhancing the injection locking range of spin torque oscillators through mutual coupling},
author = { M. Romera and P. Talatchian and R. Lebrun and K. J. Merazzo and P. Bortolotti and L. Vila and J. D. Costa and R. Ferreira and P. P. Freitas and M. C. Cyrille and U. Ebels and V. Cros and J. Grollier},
url = {https://aip.scitation.org/doi/abs/10.1063/1.4972346},
doi = {10.1063/1.4972346},
year = {2016},
date = {2016-01-01},
journal = {Applied Physics Letters},
volume = {109},
number = {25},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Paz, E; Ferreira, R; Freitas, P P
Linearization of Magnetic Sensors With a Weakly Pinned Free-Layer MTJ Stack Using a Three-Step Annealing Process Journal Article
IEEE Transactions on Magnetics, 52 (7), 2016.
@article{Paz2016,
title = {Linearization of Magnetic Sensors With a Weakly Pinned Free-Layer MTJ Stack Using a Three-Step Annealing Process},
author = { E. Paz and R. Ferreira and P. P. Freitas},
url = {https://ieeexplore.ieee.org/document/7399403/},
doi = {10.1109/TMAG.2016.2525772},
year = {2016},
date = {2016-01-01},
journal = {IEEE Transactions on Magnetics},
volume = {52},
number = {7},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Freitas, P P; Ferreira, R; Cardoso, S
Spintronic Sensors Journal Article
Proceedings of the IEEE, 104 (10), pp. 1894-1918, 2016.
@article{Freitas2016,
title = {Spintronic Sensors},
author = { P. P. Freitas and R. Ferreira and S. Cardoso},
url = {https://ieeexplore.ieee.org/abstract/document/7564473/},
doi = {10.1109/JPROC.2016.2578303},
year = {2016},
date = {2016-01-01},
journal = {Proceedings of the IEEE},
volume = {104},
number = {10},
pages = {1894-1918},
keywords = {},
pubstate = {published},
tppubtype = {article}
} -
2015
Arias, Ravelo S I; Muñoz, Ramírez D; Cardoso, S; Ferreira, R; Freitas, P
Note: A non-invasive electronic measurement technique to measure the embedded four resistive elements in a Wheatstone bridge sensor Journal Article
Review of Scientific Instruments, 86 (6), pp. 066109, 2015.
@article{Arias2015,
title = {Note: A non-invasive electronic measurement technique to measure the embedded four resistive elements in a Wheatstone bridge sensor},
author = {S. I. Ravelo Arias and D. Ramírez Muñoz and S. Cardoso and R. Ferreira and P. Freitas},
doi = {10.1063/1.4923280},
year = {2015},
date = {2015-06-01},
journal = {Review of Scientific Instruments},
volume = {86},
number = {6},
pages = {066109},
publisher = {AIP Publishing},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Ravelo, A; Sergio, I; Ramirez, D; Cardoso, S; Ferreira, R; Freitas, P P
Total ionizing dose (TID) evaluation of magnetic tunnel junction (MTJ) current sensors Journal Article
Sensors and Actuators a-Physical, 225 (119-127), 2015.
@article{Ravelo2015,
title = {Total ionizing dose (TID) evaluation of magnetic tunnel junction (MTJ) current sensors},
author = {A. Ravelo and I. Sergio and D. Ramirez and S. Cardoso and R. Ferreira and P. P. Freitas},
year = {2015},
date = {2015-04-15},
journal = {Sensors and Actuators a-Physical},
volume = {225},
number = {119-127},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Valadeiro, J; Amaral, J; Leitao, D C; Ferreira, R; Cardoso, S; Freitas, P P
Strategies for pTesla Field Detection Using Magnetoresistive Sensors With a Soft Pinned Sensing Layer Journal Article
IEEE Trans. Magn, 51 (1), pp. 4400204, 2015.
@article{Valadeiro2015,
title = {Strategies for pTesla Field Detection Using Magnetoresistive Sensors With a Soft Pinned Sensing Layer},
author = {J. Valadeiro and J. Amaral and D. C. Leitao and R. Ferreira and S. Cardoso and P. P. Freitas},
year = {2015},
date = {2015-02-02},
journal = {IEEE Trans. Magn},
volume = {51},
number = {1},
pages = {4400204},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Sievers, S; Liebing, N; Serrano-Guisan, S; Ferreira, R; E. Paz, Caprile A; Manzin, A; Pasquale, M; Skowronski, W; Stobiecki, T; Rott, K; Reiss, G; Langer, J; Ocker, B; Schumacher, H W
Toward Wafer Scale Inductive Characterization of Spin-Transfer Torque Critical Current Density of Magnetic Tunnel Junction Stacks Journal Article
IEEE Trans. Magn, 51 (1), pp. 1400804, 2015.
@article{Sievers2015,
title = {Toward Wafer Scale Inductive Characterization of Spin-Transfer Torque Critical Current Density of Magnetic Tunnel Junction Stacks},
author = {S. Sievers and N. Liebing and S. Serrano-Guisan and R. Ferreira and E. Paz, A. Caprile and A. Manzin and M. Pasquale and W. Skowronski and T. Stobiecki and K. Rott and G. Reiss and J. Langer and B. Ocker and H. W. Schumacher},
doi = {10.1109/TMAG.2014.2357808},
year = {2015},
date = {2015-02-02},
journal = {IEEE Trans. Magn},
volume = {51},
number = {1},
pages = {1400804},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Caprile, A; Manzin, A; Coisson, M; Pasquale, M; Schumacher, H W; Liebing, N; Sievers, S; Ferreira, R; Serrano-Guisan, S; Paz, E
Static and Dynamic Analysis of Magnetic Tunnel Junctions With Wedged MgO Barrier Journal Article
IEEE Trans. Magn, 51 (1), pp. 4400304, 2015.
@article{Caprile2015,
title = {Static and Dynamic Analysis of Magnetic Tunnel Junctions With Wedged MgO Barrier},
author = {A. Caprile and A. Manzin and M. Coisson and M. Pasquale and H. W. Schumacher and N. Liebing and S. Sievers and R. Ferreira and S. Serrano-Guisan and E. Paz},
url = {http://ieeexplore.ieee.org/document/7029237/},
year = {2015},
date = {2015-02-02},
journal = {IEEE Trans. Magn},
volume = {51},
number = {1},
pages = {4400304},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Costa, JD ; Serrano-Guisan, S; Borme, J; Deepak, FL ; Tarequzzaman, M; Paz, E; Ventura, J; Ferreira, R; Freitas, PP
Impact of MgO Thickness on the Performance of Spin-Transfer Torque Nano-Oscillators Journal Article
IEEE Transactions on Magnetics , 51 (11), 2015.
@article{Costa2015,
title = {Impact of MgO Thickness on the Performance of Spin-Transfer Torque Nano-Oscillators},
author = {Costa, JD and Serrano-Guisan, S and Borme, J and Deepak, FL and Tarequzzaman, M and Paz, E and Ventura, J and Ferreira, R and Freitas, PP},
url = {ieeexplore.ieee.org/document/7117429/},
doi = {10.1109/TMAG.2015.2441141},
year = {2015},
date = {2015-01-01},
journal = {IEEE Transactions on Magnetics },
volume = {51},
number = {11},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Costa, Margaret ; Gaspar, Joao ; Ferreira, Ricardo ; Paz, Elvira ; Fonseca, Helder ; Martins, Marco ; Cardoso, Susana ; Freitas, Paulo P
Integration of magnetoresistive sensors with atomic force microscopy cantilevers for scanning magnetoresistance microscopy applications Journal Article
IEEE Transactions on Magnetics, 51 , 2015.
@article{M.Costa2015,
title = {Integration of magnetoresistive sensors with atomic force microscopy cantilevers for scanning magnetoresistance microscopy applications},
author = {Costa, Margaret and Gaspar, Joao and Ferreira, Ricardo and Paz, Elvira and Fonseca, Helder and Martins, Marco and Cardoso, Susana and Freitas, Paulo P.},
year = {2015},
date = {2015-01-01},
journal = {IEEE Transactions on Magnetics},
volume = {51},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Leitao, Diana C; Silva, Ana V; Paz, Elvira; Ferreira, Ricardo; Cardoso, Susana; Freitas, Paulo P
Magnetoresistive nanosensors: controlling magnetism at the nanoscale Journal Article
Nanotechnology, 27 (4), 2015.
@article{Leitao2015,
title = {Magnetoresistive nanosensors: controlling magnetism at the nanoscale},
author = { Diana C. Leitao and Ana V. Silva and Elvira Paz and Ricardo Ferreira and Susana Cardoso and Paulo P. Freitas},
year = {2015},
date = {2015-01-01},
journal = {Nanotechnology},
volume = {27},
number = {4},
keywords = {},
pubstate = {published},
tppubtype = {article}
} -
2014
D. C. Leitao E. Paz, Silva Moskaltsova Knudde Deepak Ferreira Cardoso A A S F L R S; Freitas, P P
Nanoscale Magnetic Tunnel Junction Sensing Devices With Soft Pinned Sensing Layer and Low Aspect Ratio Journal Article
IEEE Trans. Magn, 50 (11), pp. 4410508, 2014.
@article{Leitao2014,
title = {Nanoscale Magnetic Tunnel Junction Sensing Devices With Soft Pinned Sensing Layer and Low Aspect Ratio},
author = {D. C. Leitao, E. Paz, A. Silva, A. Moskaltsova, S. Knudde, F. L. Deepak, R. Ferreira, S. Cardoso and P. P. Freitas},
doi = {10.1109/tmag.2014.2320606},
year = {2014},
date = {2014-12-02},
journal = {IEEE Trans. Magn},
volume = {50},
number = {11},
pages = {4410508},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Cardoso, F A; Rosado, L S; Franco, F; Ferreira, R; Paz, E; Cardoso, S; Ramos, P M; Piedade, M; Freitas, P P
Improved Magnetic Tunnel Junctions Design for the Detection of Superficial Defects by Eddy Currents Testing Journal Article
IEEE Trans. Magn, 50 (11), pp. 6201304, 2014.
@article{Cardoso2014b,
title = {Improved Magnetic Tunnel Junctions Design for the Detection of Superficial Defects by Eddy Currents Testing},
author = {F. A. Cardoso and L. S. Rosado and F. Franco and R. Ferreira and E. Paz and S. Cardoso and P. M. Ramos and M. Piedade and P. P. Freitas},
doi = {10.1109/TMAG.2014.2326959},
year = {2014},
date = {2014-12-02},
journal = {IEEE Trans. Magn},
volume = {50},
number = {11},
pages = {6201304},
keywords = {},
pubstate = {published},
tppubtype = {article}
}X. Q. Bao R. Ferreira, Paz Leitao Silva Cardoso Freitas E D A S P P; F.Liu, L
Ordered arrays of tilted silicon nanobelts with enhanced solar hydrogen evolution performance Journal Article
Nanoscale, 6 , pp. 2097-2101, 2014.
@article{Bao2014,
title = {Ordered arrays of tilted silicon nanobelts with enhanced solar hydrogen evolution performance},
author = {X. Q. Bao, R. Ferreira, E. Paz, D. Leitao, A. Silva, S. Cardoso, P.P. Freitas and L. F.Liu},
year = {2014},
date = {2014-10-03},
journal = {Nanoscale},
volume = {6},
pages = {2097-2101},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Roldán, A; Roldán, J B; Reig, C; Cardoso, S; Cardoso, F; Ferreira, R; Freitas, P P
An in-depth noise model for giant magnetoresistance current sensors for circuit design and complementary metal–oxide–semiconductor integration Journal Article
Journal of Applied Physics, 115 (17), pp. 17E514, 2014.
@article{Roldn2014,
title = {An in-depth noise model for giant magnetoresistance current sensors for circuit design and complementary metal–oxide–semiconductor integration},
author = {A. Roldán and J. B. Roldán and C. Reig and S. Cardoso and F. Cardoso and R. Ferreira and P. P. Freitas},
doi = {10.1063/1.4865771},
year = {2014},
date = {2014-05-01},
journal = {Journal of Applied Physics},
volume = {115},
number = {17},
pages = {17E514},
publisher = {AIP Publishing},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Cardoso, S; Leitao, D C; Gameiro, L; Cardoso, F; Ferreira, R; Paz, E; Freitas, P P
Magnetic tunnel junction sensors with pTesla sensitivity Journal Article
Microsyst. Technol., 20 , pp. 793-802, 2014.
@article{Cardoso2014,
title = {Magnetic tunnel junction sensors with pTesla sensitivity},
author = {S. Cardoso and D. C. Leitao and L. Gameiro and F. Cardoso and R. Ferreira and E. Paz and P. P. Freitas},
year = {2014},
date = {2014-04-02},
journal = {Microsyst. Technol.},
volume = {20},
pages = {793-802},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Z. Hou A. Silva, Leitao Ferreira Cardoso D C R S; Freitas, P P
Micromagnetic and magneto-transport simulations of nanodevices based on MgO tunnel junctions for memory and sensing applications Journal Article
Physica B: Condensed Matter, 435 , pp. 163-167, 2014.
@article{Hou2014,
title = {Micromagnetic and magneto-transport simulations of nanodevices based on MgO tunnel junctions for memory and sensing applications},
author = {Z. Hou, A. Silva, D. C. Leitao, R. Ferreira, S. Cardoso and P. P. Freitas},
doi = {10.1016/j.physb.2013.09.039},
year = {2014},
date = {2014-02-15},
journal = {Physica B: Condensed Matter},
volume = {435},
pages = {163-167},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Guo, D W; Cardoso, F A; Ferreira, R; Paz, E; Cardoso, S; Freitas, P P
MgO-based magnetic tunnel junction sensors array for non-destructive testing applications Journal Article
J. Appl. Phys., 115 , pp. 17E513, 2014.
@article{Guo2014,
title = {MgO-based magnetic tunnel junction sensors array for non-destructive testing applications},
author = {D. W. Guo and F. A. Cardoso and R. Ferreira and E. Paz and S. Cardoso and P. P. Freitas},
doi = {10.1063/1.4863933},
year = {2014},
date = {2014-02-15},
journal = {J. Appl. Phys.},
volume = {115},
pages = {17E513},
keywords = {},
pubstate = {published},
tppubtype = {article}
}F. A. Cardoso L. Rosado, Ferreira Paz Cardoso Ramos Piedade R E S P M M; Freitas, P P
Magnetic tunnel junction based eddy current testing probe for detection of surface defects Journal Article
J. Appl. Phys., 115 (17), pp. 15E16, 2014.
@article{Cardoso2014b,
title = {Magnetic tunnel junction based eddy current testing probe for detection of surface defects},
author = {F. A. Cardoso, L. Rosado, R. Ferreira, E. Paz, S. Cardoso, P. M. Ramos, M. Piedade and P. P. Freitas},
doi = {10.1063/1.4864045},
year = {2014},
date = {2014-02-02},
journal = {J. Appl. Phys.},
volume = {115},
number = {17},
pages = {15E16},
keywords = {},
pubstate = {published},
tppubtype = {article}
}D. C. Leitao A. Silva, Ferreira Paz Deepack Cardoso R E F L S; Freitas, P P
Linear nanometric tunnel junction sensors with exchange pinned sensing layer Journal Article
J. App. Phys., 115 (17), pp. 17E526, 2014.
@article{Leitao2014b,
title = {Linear nanometric tunnel junction sensors with exchange pinned sensing layer},
author = {D. C. Leitao, A. Silva, R. Ferreira, E. Paz, F. L. Deepack, S. Cardoso and P. P. Freitas},
doi = {doi/10.1063/1.4869163},
year = {2014},
date = {2014-01-03},
journal = {J. App. Phys.},
volume = {115},
number = {17},
pages = {17E526},
keywords = {},
pubstate = {published},
tppubtype = {article}
} -
2013
E. Paz S. Serrano-Guisan, Ferreira R; Freitas, P P
Room temperature direct detection of low frequency magnetic fields in the 100 pT/Hz(0.5) range using large arrays of magnetic tunnel junctions Journal Article
J. App. Phys., 115 (17), pp. 17E501, 2013.
@article{Paz2013,
title = {Room temperature direct detection of low frequency magnetic fields in the 100 pT/Hz(0.5) range using large arrays of magnetic tunnel junctions},
author = {E. Paz, S. Serrano-Guisan, R. Ferreira and P. P. Freitas},
doi = {10.1063/1.4859036},
year = {2013},
date = {2013-10-01},
journal = {J. App. Phys.},
volume = {115},
number = {17},
pages = {17E501},
keywords = {},
pubstate = {published},
tppubtype = {article}
}A. Silva D. Leitao, Huo Macedo Ferreira Paz Deepak Cardoso Z R R E F L S; Freitas, P P
Switching Field Variation in MgO Magnetic Tunnel Junction Nanopillars: Experimental Results and Micromagnetic Simulations Journal Article
IEEE Trans. Magn, 49 (7), pp. 4405-4408, 2013.
@article{Silva2013,
title = {Switching Field Variation in MgO Magnetic Tunnel Junction Nanopillars: Experimental Results and Micromagnetic Simulations},
author = {A. Silva, D. Leitao, Z. Huo, R. Macedo, R. Ferreira,E. Paz, F. L. Deepak, S. Cardoso and P. P. Freitas},
year = {2013},
date = {2013-07-15},
journal = {IEEE Trans. Magn},
volume = {49},
number = {7},
pages = {4405-4408},
keywords = {},
pubstate = {published},
tppubtype = {article}
}A. Lopes S. Cardoso, Ferreira Paz Deepak Sanchez Ramirez Ravelo R E F L J D S; Freitas, P P
MgO Magnetic Tunnel Junction Electrical Current Sensor With Integrated Ru Thermal Sensor Journal Article
IEEE Trans. Magn, 49 (7), pp. 3866-3869, 2013.
@article{Lopes2013,
title = {MgO Magnetic Tunnel Junction Electrical Current Sensor With Integrated Ru Thermal Sensor},
author = {A. Lopes, S. Cardoso, R. Ferreira, E. Paz, F. L. Deepak, J. Sanchez, D. Ramirez, S. Ravelo, and P. P. Freitas},
doi = {10.1109/TMAG.2013.2246550},
year = {2013},
date = {2013-07-15},
journal = {IEEE Trans. Magn},
volume = {49},
number = {7},
pages = {3866-3869},
keywords = {},
pubstate = {published},
tppubtype = {article}
}J. Amaral V. Pinto, Costa Gaspar Ferreira Paz Cardoso T J R E S; Freitas, P P
Integration of TMR Sensors in Silicon Microneedles for Magnetic Measurements of Neurons Journal Article
IEEE Trans. Magn, 49 (7), pp. 3515-3515, 2013.
@article{Amaral2013,
title = {Integration of TMR Sensors in Silicon Microneedles for Magnetic Measurements of Neurons},
author = {J. Amaral, V. Pinto, T. Costa, J. Gaspar, R. Ferreira, E. Paz, S. Cardoso and P. P. Freitas},
doi = {10.1109/TMAG.2013.2239274},
year = {2013},
date = {2013-07-15},
journal = {IEEE Trans. Magn},
volume = {49},
number = {7},
pages = {3515-3515},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Cardoso, S; Gameiro, L; Leitao, D C; Cardoso, F; Ferreira, R; Paz, E; Freitas, P P; Schmid, U; Aldavero, J; LeesterSchaede, M
Magnetic tunnel junction sensors with pTesla sensitivity for biomedical imaging Journal Article
Smart Sensors, Actuators, and Mems, pp. 8763, 2013.
@article{Cardoso2013,
title = {Magnetic tunnel junction sensors with pTesla sensitivity for biomedical imaging},
author = {S. Cardoso and L. Gameiro and D. C. Leitao and F. Cardoso and R. Ferreira and E. Paz and P. P. Freitas and U. Schmid and J. Aldavero and M. LeesterSchaede},
doi = {10.1117/12.2018070},
year = {2013},
date = {2013-05-17},
journal = {Smart Sensors, Actuators, and Mems},
pages = {8763},
keywords = {},
pubstate = {published},
tppubtype = {article}
}F. Delgado K. Lopez, Ferreira R; Fernández-Rossier, J
Intrinsic Spin Noise in MgO Magnetic Tunnel Junctions Journal Article
Appl. Phys. Lett. , 102 (63102), 2013.
@article{Delgado2013,
title = {Intrinsic Spin Noise in MgO Magnetic Tunnel Junctions},
author = {F. Delgado, K. Lopez, R. Ferreira and J. Fernández-Rossier},
url = {https://doi.org/10.1063/1.4791594},
doi = {10.1063/1.4791594},
year = {2013},
date = {2013-02-12},
journal = {Appl. Phys. Lett. },
volume = {102},
number = {63102},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Liebing, Niklas; Serrano-Guisan, Santiago; Krzysteczko, Patryk; Rott, Karsten; "u, G; "u, J; Ocker, Berthold; Schumacher, Hans Werner
Tunneling magneto thermocurrent in CoFeB/MgO/CoFeB based magnetic tunnel junctions Journal Article
Applied Physics Letters, 102 (24), pp. 242413, 2013.
@article{Liebing2013,
title = {Tunneling magneto thermocurrent in CoFeB/MgO/CoFeB based magnetic tunnel junctions},
author = { Niklas Liebing and Santiago Serrano-Guisan and Patryk Krzysteczko and Karsten Rott and G{"u}nter Reiss and J{"u}rgen Langer and Berthold Ocker and Hans Werner Schumacher},
url = {https://doi.org/10.1063/1.4811737},
doi = {10.1063/1.4811737},
year = {2013},
date = {2013-01-01},
journal = {Applied Physics Letters},
volume = {102},
number = {24},
pages = {242413},
publisher = {AIP Publishing},
keywords = {},
pubstate = {published},
tppubtype = {article}
} -
2012
Arias, S; Munoz, D; Moreno, J; Cardoso, S; Ferreira, R; Freitas, P P
Fractional Modeling of the AC Large-Signal Frequency Response in Magnetoresistive Current Sensors Journal Article
Sensors, 13 (12), pp. 17516-17533, 2012.
@article{Arias2012,
title = {Fractional Modeling of the AC Large-Signal Frequency Response in Magnetoresistive Current Sensors},
author = {S. Arias and D. Munoz and J. Moreno and S. Cardoso and R. Ferreira and P. P. Freitas},
url = {https://doi.org/10.3390/s131217516},
doi = {10.3390/s131217516},
year = {2012},
date = {2012-12-17},
journal = {Sensors},
volume = {13},
number = {12},
pages = {17516-17533},
keywords = {},
pubstate = {published},
tppubtype = {article}
}J. Ventura J. M. Teixeira, Paz J.S.Amaral J.D.Costa P.Araujo Cardoso Ferreira E J S R; P.P.Freitas,
The influence of annealing on the bimodal distribution of blocking temperatures of exchange biased bilayers Journal Article
Phys. Status Solidi RRL, 7 (9), pp. 676-680, 2012.
@article{Ventura2012,
title = {The influence of annealing on the bimodal distribution of blocking temperatures of exchange biased bilayers},
author = {J. Ventura, J. M. Teixeira, E. Paz, J.S.Amaral, J.D.Costa, J. P.Araujo, S. Cardoso, R. Ferreira, and P.P.Freitas},
year = {2012},
date = {2012-12-02},
journal = {Phys. Status Solidi RRL},
volume = {7},
number = {9},
pages = {676-680},
keywords = {},
pubstate = {published},
tppubtype = {article}
}R. Ferreira E. Paz, Freitas Wang P P J; Xue, S
Large Area and Low Aspect Ratio Linear Magnetic Tunnel Junctions with a Soft-Pinned Sensing Layer Journal Article
IEEE Trans. Magn, 48 (11), pp. 3719, 2012.
@article{Ferreira2012,
title = {Large Area and Low Aspect Ratio Linear Magnetic Tunnel Junctions with a Soft-Pinned Sensing Layer},
author = {R. Ferreira, E. Paz, P. P. Freitas, J. Wang and S. Xue},
url = {https://doi.org/10.1109/TMAG.2012.2200468},
doi = {10.1109/TMAG.2012.2200468},
year = {2012},
date = {2012-10-18},
journal = {IEEE Trans. Magn},
volume = {48},
number = {11},
pages = {3719},
keywords = {},
pubstate = {published},
tppubtype = {article}
}R. Ferreira E. Paz, Freitas Ribeiro Germano P P J J; Sousa, L
2-axis Magnetometers Based on Full Wheatstone Bridges Incorporating Magnetic Tunnel Junctions Connected in Series Journal Article
IEEE Trans. Magn, 48 (11), pp. 4107, 2012.
@article{Ferreira2012b,
title = {2-axis Magnetometers Based on Full Wheatstone Bridges Incorporating Magnetic Tunnel Junctions Connected in Series},
author = {R. Ferreira, E. Paz, P. P. Freitas, J. Ribeiro, J. Germano and L. Sousa},
url = {https://doi.org/10.1109/TMAG.2012.2202381},
doi = {10.1109/TMAG.2012.2202381},
year = {2012},
date = {2012-10-18},
journal = {IEEE Trans. Magn},
volume = {48},
number = {11},
pages = {4107},
keywords = {},
pubstate = {published},
tppubtype = {article}
}J. Sanchez D. Ramirez, Ravelo Lopes Cardoso Ferreira S A S R; Freitas, P P
Electrical Characterization of a Magnetic Tunnel Junction Current Sensor for Industrial Applications Journal Article
IEEE Trans. Magn, 48 (11), pp. 2823, 2012.
@article{Sanchez2012,
title = {Electrical Characterization of a Magnetic Tunnel Junction Current Sensor for Industrial Applications},
author = {J. Sanchez, D. Ramirez, S. Ravelo, A. Lopes, S. Cardoso, R. Ferreira and P. P. Freitas},
url = {https://doi.org/10.1109/TMAG.2012.2196422},
doi = {10.1109/TMAG.2012.2196422},
year = {2012},
date = {2012-10-18},
journal = {IEEE Trans. Magn},
volume = {48},
number = {11},
pages = {2823},
keywords = {},
pubstate = {published},
tppubtype = {article}
}R. J. Janeiro L. Gameiro, Lopes Cardoso Ferreira Paz A S R E; Freitas, P P
Linearization and Field Detectivity in Magnetic Tunnel Junction Sensors Connected in Series Incorporating 16nm-thick NiFe Free Layers Journal Article
IEEE Trans. Magn, 48 (11), pp. 4111, 2012.
@article{Janeiro2012,
title = {Linearization and Field Detectivity in Magnetic Tunnel Junction Sensors Connected in Series Incorporating 16nm-thick NiFe Free Layers},
author = {R. J. Janeiro, L. Gameiro, A. Lopes, S. Cardoso, R. Ferreira, E. Paz and P. P. Freitas },
doi = {10.1109/TMAG.2012.2202887},
year = {2012},
date = {2012-10-18},
journal = {IEEE Trans. Magn},
volume = {48},
number = {11},
pages = {4111},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
GROUP LEADER
THE TEAM
Alex Jenkins
Staff Researcher
Elvira Paz
Staff Researcher
Tim Böhnert
Staff Researcher
Lara San-Emeterio
Research Fellow
Leandro Martins
Research Fellow
Paulo Coelho
Research Engineer
also on the picture
Cosimo Spagnolo and Mohamed Belmoubarik
Research Engineers from Nanodevices
Luana Benetti and Oscar Ojeda Toro
Visitor from Universidade Federal de Santa Maria and Universidade Federal de Viçosa
Arthur de Sousa Lopes Moreira and Marion Vieira
Master students from Université Clermont Auvergne (UCA)
Lianwei Wang, En Ping Tu and Hefu Han
from LerTech Co.,Ltd
Previous Members
Diogo Costa
PhD Student
Moved to IMEC after working at INL during 2013-2017
Bertrand Lacoste
Old Group Member
Moved to Champalimaud after working at INL during 2013-2015
Mohammad Tarequzzaman
Old Group Member (Research Fellow)
Santiago Serrano-Guisan
Old Group Member
Moved to Headway after working at INL during 2013-2015