A homovalent doping in PMN ceramics by using lithium and scandium cations

被引：3

作者：

Paula, A. J. ^{[1
]}

Cavalheiro, A. A. ^{[2
]}

Bruno, J. C. ^{[2
]}

Zaghete, M. A. ^{[1
]}

Longo, Elson ^{[1
]}

Varela, J. A. ^{[1
]}

机构：

[1] UNESP, Inst Quim, BR-14801970 Araraquara, SP, Brazil

[2] UNESP, Inst Biociencias, Depto Quim, BR-18618000 Botucatu, SP, Brazil

来源：

MATERIALS CHEMISTRY AND PHYSICS | 2008年 / 112卷 / 03期

基金：

巴西圣保罗研究基金会;

关键词：

Pb(Mg1/3Nb2/3)O-3; Ceramics; Powder diffraction; Ferroelectrics; Rietveld analysis;

D O I：

10.1016/j.matchemphys.2008.06.061

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The Mg2+ homovalent substitution by Li+/Sc3+ cations at the B-site sub-lattice of the lead magnesium niobate (PMN) perovskite structure was studied in this work. Through structural and electrical analyses, it was observed that the dopant pair effectively substituted the Mg cation, although an addition limit close to 2.5 mol% of dopants was observed. Up to this concentration level, the dopant pair does not affect the perovskite phase stability, and thus, pyrochlore free ceramics with a T-m value of -6 degrees C and 19,000 of electric permittivity were obtained. As a consequence of the substitution, the 1:1 chemical ordering at the B-site was changed, leading to a less diffuse ferroelectric-paraelectric phase transition even despite the increase of the relaxor character. However, a 5.0 mol% addition of Li/Sc provoked the precipitation of a small quantity of pyrochlore phase that caused a deterioration of the ceramic electrical properties. (C) 2008 Elsevier B.V. All rights reserved.

引用

页码：886 / 891

页数：6

共 22 条

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