Structure, ferroelectric and dielectric properties of Bi_2 WO_6 with different bismuth content  

作　　者：王晓娟 龚志强 朱骏 陈小兵 

机构地区：[1]College of Physics and Electronic Engineering, Changshu Institute of Technology [2]College of Physics Science and Technology, Yangzhou University [3]Laboratory for Climate Studies, National Climate Center, China Meteorological Administration

出　　处：《Chinese Physics B》2009年第2期803-809,共7页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No 10274066);the Natural Science Foundation of Jiangsu Province, China (Grant No BK2005052)

摘　　要：This paper reports that the Bi2WO6 ferroelectric ceramics with excess Bi2O3 of 0.0, 2.0, 3.5 and 5.0wt.% of the stoichiometric composition are prepared by the conventional solid-state reaction method. Their microstructure, ferroelectric properties, the concentration and mobility of the defects have been analysed systematically. With increasing Bi content, the remnant polarization decreases, and the broken-down voltage increases. The optimum Bi excess, 3.5, lowers the oxygen vacancy concentration, while further Bi-addition brings about more defects. The activation energies fitted from cole-cole plots are 0.97 eV, 1.07 eV, 1.18 eV, and 1.33 eV, respectively. This suggests that the mobility of the defects is weakened by Bi-addition, which may be due to the increase of the ratio of the number of Bi2O2 layers to that of the oerovskite blocks.This paper reports that the Bi2WO6 ferroelectric ceramics with excess Bi2O3 of 0.0, 2.0, 3.5 and 5.0wt.% of the stoichiometric composition are prepared by the conventional solid-state reaction method. Their microstructure, ferroelectric properties, the concentration and mobility of the defects have been analysed systematically. With increasing Bi content, the remnant polarization decreases, and the broken-down voltage increases. The optimum Bi excess, 3.5, lowers the oxygen vacancy concentration, while further Bi-addition brings about more defects. The activation energies fitted from cole-cole plots are 0.97 eV, 1.07 eV, 1.18 eV, and 1.33 eV, respectively. This suggests that the mobility of the defects is weakened by Bi-addition, which may be due to the increase of the ratio of the number of Bi2O2 layers to that of the oerovskite blocks.

关 键 词：ferroelectric ceramics Bi2WO6 oxygen vacancy x-ray photoemission spectroscopy 

分 类 号：O482.4[理学—固体物理]