The Role of Particle Contact in Densification of FLASH Sintered Potassium Sodium Niobate

authors	Serrazina, R; Senos, AMOR; Pereira, L; Dean, JS; Reaney, IM; Vilarinho, PM
nationality	International
journal	EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
author keywords	FLASH sintering; Niobium; KNN; Finite element modelling; Lead-free piezoelectrics; Materials science
keywords	TEMPERATURE DISTRIBUTION; MICROSTRUCTURE
abstract	Potassium sodium niobate, K0.5Na0.5NbO3(KNN) is a lead-free piezoelectric with the potential to replace lead zirconate titanate (PZT) in electromechanical applications. Due to its cuboid particle morphology and volatile elements, monophasic and dense ceramics are difficult to obtain via conventional sintering. In this work, isothermal FLASH sintering produced uniformly densified KNN ceramics at 900 degrees C, 200 degrees C lower than conventional sintering. Specific surface area (SSA) analysis ofpre-FLASHceramics revealed that a 30 min isothermal hold at 900 degrees C, before the application of electric field, increased the contact area between particles and was crucial to promote uniform densification. Finite element modelling (FEM) revealed why density is more uniform when using isothermal heating compared with a constant heating rate, commonly used in FLASH sintering. These results extend our understanding of FLASH sintering and illustrate its relevance for the development of lead-free piezoelectrics.
publisher	WILEY-V C H VERLAG GMBH
issn	1434-1948
isbn	1099-0682
year published	2020
volume	2020
issue	39
beginning page	3720
ending page	3728
digital object identifier (doi)	10.1002/ejic.202000458
web of science category	Chemistry, Inorganic & Nuclear
subject category	Chemistry
unique article identifier	WOS:000562261700001