FLASH

Potassium-Sodium-Niobate (KNN) is getting increasing importance as lead-free piezoelectric functional material. However, monophasic dense KNN products are yet difficult to obtain and this project proposes a new method to densify materials abruptly above a threshold condition, FLASH sintering (FS), using a combination of temperature and electrical field directly applied to the specimen. A clear understanding of the phenomena does not exist yet. The present work aims to exploit FS and study the science behind it with the following objectives: (i) To investigate the dependence of FS on KNN dimensionality (bulk, films, nanoparticles) (ii) To identify the densification mechanisms in KNN FS and effects of electrical field (iii) To develop alternative sintering techniques for functional oxides aiming to decrease the thermal budget (iv) To prove the concept for low temperature sintering of KNN thin films on flexible substrates, never explored by FS, and extend it to other lead free oxides.