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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Structural ordering and dielectric properties of Ba3CaNb2O9-based microwave ceramics

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Rodrigues, J. E. F. S. ; Castro, P. J. ; Pizani, P. S. ; Correr, W. R. ; Hernandes, A. C.
Total Authors: 5
Document type: Journal article
Source: CERAMICS INTERNATIONAL; v. 42, n. 16, p. 18087-18093, DEC 2016.
Web of Science Citations: 7

Ba3CaNb2O9 is a 1:2 ordered perovskite which presents a trigonal cell within the D-3d(3) space group. Dense ceramics of Ba3CaNb2O9 were prepared by the solid-state reaction route, and their microwave dielectric features were evaluated as a function of the sintering time. From Raman spectroscopy, by using group theory calculations, we were able to recognize the coexistence of the 1:1 and 1:2 ordering types in all samples, in which increasing the sintering time tends to reduce the 1:1 domain, leading to an enhancement of the unloaded quality factor. We concluded that this domain acts as a lattice vibration damping, consequently raising the dielectric loss at microwave frequencies. The best microwave dielectric parameters were determined in ceramics sintered at 1500 degrees C for 32h: epsilon' similar to 43; Q(u) x f(r) = 15,752 GHz; tau(f) similar to 278 ppm degrees C-1. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved. (AU)

FAPESP's process: 08/57872-1 - National Institute for Materials Science in Nanotechnology
Grantee:Elson Longo da Silva
Support type: Research Projects - Thematic Grants
FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
Grantee:Elson Longo da Silva
Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC