La_(0.67)Ba_(0.33)MnO_3中Cu掺杂对电特性和室温磁电阻的影响  

Electrical behavior and enhancement of room temperature magnetoresistance induced by the Cu doping in 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：《功能材料》2004年第5期555-557,共3页Journal of Functional Materials

基　　金：国家重点基础研究专项经费资助项目(G19980613010)

摘　　要：　在溶胶 凝胶法制备的La0.67Ba0.33MnO3(LBMO)微粉中掺入CuO粉,制成一系列(LBMO)/(CuO)x(x=0.01～0.1,为摩尔比)掺杂材料,实验结果发现,随着Cu掺杂量的增加,材料的磁化强度和居里温度变化不大,材料的电阻率先快速减小,而后缓慢增大,当x=0.01时在全温范围内电阻率都达到最小值,这与Cu离子的价态变化有关。实验还发现Cu离子的掺入可以使材料的室温磁电阻逐步提高,当掺入10%的Cu时,室温磁电阻比达到-8.4%,比未掺杂的LBMO提高了50%。低电阻率导电陶瓷材料和大的室温磁电阻效应都是应用研究所关注的课题。A series of samples (La0.67Ba0.33MnO3)/ (CuO)x(x=0.01-0.1, the mol ratio) were prepared by doping CuO in La0.67Ba0.33MnO3 (LBMO) powder synthesized by the sol-gel method. The experimental results revealed that with increasing Cu dopant, the magnetization and Curie temperature of the materials change a little, the resistivity decreases rapidly first and then increases slowly. When x=0.01, the resistivity of the sample reaches the minimum in the entire temperature region. These behaviors are related to the change in the valence state of Cu ions. The experiments also showed that doping Cu can gradually increase the room temperature magnetoresistance of the materials. When x=0.1, magnetoresistance ratio at room temperature reaches -8.4% which is increased by 50% than that of undoped LBMO. The conductive ceramics with low resistivity and large magnetoresistance effect at room temperature were the interesting topics of the application researches.

关 键 词：稀土掺杂锰氧化物 庞磁电阻效应 颗粒体系 导电陶瓷 室温磁电阻 

分 类 号：O482[理学—固体物理] TB34[理学—物理]