文档介绍：Materials Research Bulletin 39 (2004) 2127–2135
ate/matresbu
Microwave dielectric properties of (Pb1À3x/2Lax)(Mg1/2W1/2)O3
Bian Jianjiang*, Gao Hong Bo, Wang Xiaowu
Department of anic Materials, Shanghai University, 149 Yanchang Road,
Zhabei District, Shanghai 200072, PR China
Received 6 August 2003; received in revised form 2 March 2004; accepted 23 June 2004
Abstract
La modified Pb(Mg1/2W1/2)O3 were prepared by solid-state reaction process, and the sintering behavior,
microstructure and microwave dielectric properties were investigated by X-ray powder diffraction (XRD), Raman
scattering and work analyzer in this paper. A series of single phase perovskite type solid solutions with A-site
vacancies (Pb1À3x/2Lax(Mg1/2W1/2)O3 (0 x 2/3)) were formed. The solid solution took cubic perovskite type
structure (Fm3m) with random distribution of A-site vacancies when 0 < x < , and tetragonal or orthorhombic
structure with the ordering of A-site vacancies when x 2/3. The dielectric constant and temperature
coefficient of resonant frequency decrease with increasing La content. Relatively bination microwave
dielectric properties were obtained for x = : er = ; Q Â f = 18098; and tf = À ppm/8C.
# 2004 Elsevier Ltd. All rights reserved.
Keywords: A. Ceramics; C. X-ray diffraction; D. Dielectric properties
1. Introduction
With the development