La_(0.67)Sr_(0.33)MnO_3中Bi的掺杂效应  

Effects of Bi addition on the properties of La_(0.67)Sr_(0.33)MnO_3

作　　者：黄宝歆[1,2] 刘宜华[1] 原晓波[1] 王成建[1] 陈卫平[3] 张汝贞[1] 梅良模[1] 

机构地区：[1]山东大学物理与微电子学院,晶体材料国家重点实验室 [2]潍坊学院物理系,潍坊261043 [3]浙江台州学院物理系

出　　处：《功能材料与器件学报》2004年第3期303-306,312,共5页Journal of Functional Materials and Devices

基　　金：国家重点基础研究专项经费资助项目(G19980613010)

摘　　要：将Bi2O3掺杂到用溶胶-凝胶法制备的La0.67Sr0.33MnO3(LSMO)微粉中,XRD测量结果证实有过量的Bi析出。随着Bi掺杂量的增加,LSMO/(Bi2O3)x/2材料电阻率发生明显变化,在x=(0-0.10)摩尔比的掺杂范围内,电阻率先上升后突然下降。当x=0.1时,电阻率比未掺杂样品下降了一个数量级。Bi掺杂对低温和室温磁电阻有着完全不同的影响。低温下,随掺杂量增加,磁电阻下降;室温下Bi的微量掺杂可以使磁电阻增大,掺入x=0.03Bi使室温磁电阻由-4.4%提高到-5.6%。The samples La0.67Sr0.33MnO3/(Bi2O3)x/2 were prepared by doping Bi2O3 into the La0.67Sr0.33-MnO3 (LSMO) powder, which was synthesized by the sol-gel method. The XRD result indicates that there exists excess metal Bi in the samples. The resistivities of the samples are influenced remarkably by Bi addition. In the doping range of x=0-0.10 mol ratio, the resistivity rises firstly, and then decreases suddenly with further Bi doping. The resistivity for the sample of x=0.10 is lower than that for LSMO by one order of magnitude. Bi doping has completely different influence on MR effect whichis depended on temperature. At low temperature, the MR ratio decreases with increasing Bi doping amount while at room temperature it enhances with a small quantity of Bi addition. The x=0.03 Bi promotes the MR ratio at room temperature from -4.4%to -5.6%.

关 键 词：LA0.67SR0.33MNO3 掺杂 磁电阻效应 自旋相关散射 自旋相关隧穿 铋 LSMO 

分 类 号：O482.5[理学—固体物理]