Linking sintering stresses to nano modification in the microstructure of BaLa4Ti4O15 by transmission electron microscopy

authors	Selvaraj, NB; Fernandes, M; Reaney, IM; Abrantes, JCC; Denneulin, T; Snoeck, E; Vilarinho, PM; Senos, AM
nationality	International
journal	MATERIALS CHARACTERIZATION
author keywords	Stress; Sintering; Barium lanthanum titanate; High resolution transmission electron microscopy; Microstructure; Geometric phase analysis
keywords	STRONTIUM-TITANATE; GRAIN-GROWTH; IMAGES; ALUMINA
abstract	High quality factor and a temperature stable resonant frequency make BaLa4Ti4O15 (BLT) ceramics attractive materials for microwave applications. Aiming to exploit the effects of external stresses on the development of textured and anisotropic microstructures to optimise MW properties, the influence of applied external pressure during sintering of BLT ceramics is analysed. HRTEM and geometric phase analysis (GPA) showed that stresses applied during sintering, trigger the nucleation and growth of faults hypothesised to be due to the errors in the AO(3) layer (basal plane) stacking sequence of the hexagonal perovskite structure. The results reveal a strong correlation between the high concentration of structural defects and the development of anisotropic microstructures, which tune the properties of BLT. Stresses applied during sintering are therefore a promising tool to design material properties.
publisher	ELSEVIER SCIENCE INC
issn	1044-5803
year published	2018
volume	142
beginning page	1
ending page	8
digital object identifier (doi)	10.1016/j.matchar.2018.04.054
web of science category	Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing
subject category	Materials Science; Metallurgy & Metallurgical Engineering
unique article identifier	WOS:000440527300001