abstract
Sr2-xCaxBi4Ti5O18(x = 0, 0.05) powders synthesized by solid state route were uniaxially pressed and sintered at 1225 degrees C for 2 h. The obtained dense ceramics exhibited crystallographic anisotropy with a dominant c axis parallel to the uniaxial pressing direction which was quantified in terms of the Lotgering factor. Microstructure anisotropy of both compositions (x = 0, 0.05) consisted of plate like grains exhibiting their larger surfaces mostly perpendicular to the uniaxial pressing direction. Dielectric and ferroelectric properties of Sr2-xCaxBi4Ti5O18 ceramics were measured under an electric field (E) applied parallel and perpendicularly to uniaxial pressing direction. The obtained dielectric epsilon(R)(T) and polarization (P-E) curves depended strongly on E direction thus denoting a significant effect from microstructure and crystallographic texture. Sr2-xCaxBi4Ti5O18 properties were also significantly affected by Ca content (x): Curie temperature increased from 280 degrees C (x = 0) to 310 degrees C (x = 0.05) while epsilon(R) and remnant polarization decreased for x = 0.05. The present results are discussed within the framework of the processing and crystal structure-properties relationships of Aurivillius oxides ceramics. (C) 2010 Elsevier Ltd. All rights reserved.
keywords
TEMPLATED GRAIN-GROWTH; SINGLE-CRYSTALS; PIEZOELECTRIC PROPERTIES; ELECTRICAL-PROPERTIES; PHASE-TRANSITIONS; SOLID-SOLUTION; THIN-FILMS; BISMUTH; SRBI2TA2O9; CA
subject category
Materials Science
authors
Jin, SO; Salvado, IMM; Costa, MEV
our authors
Isabel Margarida Miranda Salvado
Associate Professor
Maria Elisabete Jorge Vieira Costa
CollaboratorGroups
G2 - Photonic, Electronic and Magnetic Materials
G5 - Biomimetic, Biological and Living Materials
acknowledgements
FCT for the financial support through the project PTDC/CTM/71643/2006