La_(0.67)Ba_(0.33)MnO_3中Bi掺杂产生的低场磁电阻增强效应  

Enhancement of Low Field Magnetoresistance in Bi-Doped La_(0.67)Ba_(0.33)MnO_3

作　　者：原晓波[1] 刘宜华[1] 黄宝歆[1] 王成建[1] 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和晶体材料国家重点实验室,山东济南250100

出　　处：《中国稀土学报》2004年第3期336-340,共5页Journal of the Chinese Society of Rare Earths

基　　金：国家重点基础研究专项经费资助项目 (G19980 613 0 10 )

摘　　要：将Bi2 O3掺杂到溶胶 凝胶法制备的La0 .6 7Ba0 .33MnO3(LBMO)微粉中 ,结果发现随着Bi的掺杂 ,材料的磁化强度和居里温度基本不变 ,但电阻率发生明显变化 ,在 0～ 10 % (摩尔分数 )的掺杂范围内 ,电阻率先急速上升后缓慢降低。掺Bi可以使低温下的低场磁电阻得到显著增强 ,但并不改变与双交换作用有关的本征磁电阻 ;掺Bi也使室温下的磁电阻得到明显增强。The studied samples were prepared by doping Bi_2O_3 into the La_(0.67)Ba_(0.33)MnO_3 powder, which was synthesized by the sol-gel technique. The results indicate that the magnetization and Curie temperature of the materials are not changed basically, but the resistivity is influenced remarkably by the Bi doping. In the doping range of 0～10% (mol fraction), the resistivity rises rapidly first, and then decreases slowly with increasing Bi doping amount. Doping Bi can evidently improve the low field magnetoresistance at low temperature, while the intrinsic magnetoresistance related to the double exchange interaction may not be changed. The Bi doping is also able to enhance the magnetoresistance at room temperature, which is favorable for the applications.

关 键 词：陶瓷材料 低场磁电阻 自旋相关散射 自旋相关隧穿 稀土 

分 类 号：O482[理学—固体物理] TB34[理学—物理]