Al^(3+)离子替代La_(0.67)Ca_(0.33)MnO_3体系的结构和输运行为研究  

Study of structural and transport properties for Al^(3+)-doping La_(2/3)Ca_(1/3)MnO_3 perovsksite manganese

作　　者：崔玉建[1] 王新燕[2] 贾广强[2] 葛洪良[1] 曹桂新[2] 张玉凤[2] 曹世勋[2] 张金仓[2] 

机构地区：[1]中国计量学院应用物理系,浙江杭州310018 [2]上海大学物理系,上海200436

出　　处：《功能材料》2004年第2期206-208,211,共4页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(10274049);浙江省自然科学基金资助项目(502122);上海市教委科技发展基金资助项目(02AK42);上海市教委重点学科建设基金资助项目(01A16)

摘　　要：　系统研究了Mn位替代的La0.67Ca0.33Mn1-xAlxO3体系的结构和输运特性。结果表明,随Al3+替代含量的增加,在整个替代范围内,晶胞体积表现出单调减小的规律。而体系的电阻率急剧增加,绝缘体 金属转变温度TIM向低温方向移动,且与Al3+替代含量存在线性关联。对少量Al3+替代含量,在T>TIM的高温区域体系的输运特性满足热激活模型,在T<TIM的低温区域满足金属输运行为。这种输运行为随Al3+替代的变化特征,可从Al3+离子对Mn3+—O2-—Mn4+双交换通道的破坏和所导致的晶格畸变方面给予解释,Al3+替代改变了电子的局域环境,进而影响到体系的输运行为。The effects of Al^(3+) doping on Mn site have been studied for the colossal magnetoresistance material La_(0.67)Ca_(0.33)MnO_3. It was found that when doping amount of Al^(3+) increases the resistivity increase rapidly. The insulator-metal transition temperature move to lower temperature and decrease linearly with Al^(3+) doping. The crystal cell parameters decrease with Al^(3+) doping. At little Al doping, the resistance satisfy thermal active modal among T>T_(IM) and metal transport property among T<T_(IM). The double exchange channel of Mn^(3+)-O^(2-)-Mn^(4+) was jammed by doping Al^(3+) and bring crystal lattice aberrance, the local environment was changed and effected the transport property of system.

关 键 词：稀土锰基氧化物 晶体结构 输运行为 钙钛矿结构 掺杂 

分 类 号：O614.33[理学—无机化学]