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.
keywords
STRONTIUM-TITANATE; GRAIN-GROWTH; IMAGES; ALUMINA
subject category
Materials Science; Metallurgy & Metallurgical Engineering
authors
Selvaraj, NB; Fernandes, M; Reaney, IM; Abrantes, JCC; Denneulin, T; Snoeck, E; Vilarinho, PM; Senos, AM
our authors
Ana Maria de Oliveira e Rocha Senos
Collaborator
João Carlos de Castro Abrantes
Professor Adjunto
Manuela Alexandra Coelho Fernandes
PhD Student
Nivas Babu Selvaraj
Post-Doc Fellowship
Paula Maria Lousada Silveirinha Vilarinho
Vice DirectorGroups
G2 - Photonic, Electronic and Magnetic Materials
G3 - Electrochemical Materials, Interfaces and Coatings
acknowledgements
The authors acknowledge Fundacao para a Ciencia e a Tecnologia (FCT), Fundo Europeu de Desenvolvimento Regional Portugal (FEDER), QREN-COMPETE Portugal, the Associate Laboratory CICECO (PEst-C/CTM/LA0011/2013) for funding support. NBS acknowledges FCT for financial support (SFRH/BPD/82158/2011). The authors acknowledge the support of European Union seventh framework programme under a contract for an integrated infrastructure initiative (312483-ESTEEM2).