Lead-free piezoelectric ceramics with nominal composition at morphotropic phase boundary BaCaTiZrO (BCTZ) prepared by different processing routes and sintered either by conventional solid-state reaction or by spark plasma sintering (SPS) techniques were comparatively investigated to observe the role of structural modifications and of microstructures on the dielectric, ferroelectric, piezoelectric and electrocaloric responses. The ceramics presented relative densities from 75% to 97% and showed variations in their phase composition as a result of variable mixing and different synthesis and sintering parameters providing local compositional heterogeneity. As result, all of the ceramics showed diffuse phase transition and ferroelectric switching responses, with parameters affected mostly by density ( between 3.
View Article and Find Full Text PDF(001)-Epitaxial La2WO6 (LWO) thin films are grown by pulsed laser deposition on (001)-oriented SrTiO3 (STO) substrates. The α-phase (high-temperature phase in bulk) is successfully stabilized with an orthorhombic structure (a = 16.585(1) Å, b = 5.
View Article and Find Full Text PDFThe crystal structure of La10W2O21, which has to be reformulated (La5.667W0.333)LaWO14□2, is best described, on average, by a 2 × 2 × 2 anion-deficient fluorite-related superstructure cubic cell, with space group F4 3m, Z = 4, and a = 11.
View Article and Find Full Text PDFWe report the synthesis, structure determination, and structure analysis of La(18)W(10)O(57), which presents 52.65 WO(3) mol % in the binary system La(2)O(3)-WO(3) in place of the previous reported compound: La(14)W(8)O(45), 53.3 WO(3) mol %.
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