Departmental Papers (MSE)

Document Type

Journal Article

Date of this Version

July 2006

Comments

Copyright The American Ceramic Society. Reprinted from Journal of the American Ceramic Society, Volume 89, Issue 7, July 2006, pages 2239-2249.

Abstract

A narrow region of Zn-vacancy-containing cubic perovskites was formed in the (1-x)Ba3(ZnNb2)O9-x)Ba3W2O9 system up to 2 mol%substitution (x=0.02). The introduction of cation vacancies enhanced the stability of the 1:2 B-site ordered form of the structure, Ba(Zn1-x-x)1/3(Nb1-xWx)2/3O3, which underwent an order–disorder transition at 1410°C, ∼35° higher than pure Ba(Zn1/3Nb2/3)O3. The Zn vacancies also accelerated the kinetics of the ordering reaction, and samples with x=0.006 comprised large ordered domains with a high lattice distortion (c/a=1.226) after a 12 h anneal at 1300°C. The tungstate-containing solid solutions can be sintered to a high density at 1390°C, and the resultant ordered ceramics exhibit some of the highest microwave dielectric Q factors (Q×f=1 18 000 at 8 GHz) reported for a niobate-based perovskite.

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Date Posted: 04 December 2006

This document has been peer reviewed.