银,钾掺杂对稀土锰钙钛矿的磁性和电性的影响  

Effects of Ag,K-Doping on Magnetic and Transport Properties of Rare Earth Manganite with Perovskite Structure

作　　者：王辽宇[1] 曹庆琪[1] 司继伟[1] 顾本喜[1] 都有为[1] 

机构地区：[1]南京大学物理系固体微结构国家实验室江苏省纳米技术重点实验室,江苏南京210093

出　　处：《中国稀土学报》2007年第3期309-313,共5页Journal of the Chinese Society of Rare Earths

基　　金：国家重点基础研究规划(973)资助项目(2005CB23605)

摘　　要：用固相反应方法制备了银和钾掺杂稀土锰钙钛矿氧化物Ag-(La0.92K0.04MnO3)n,研究了该系统的电性和磁性。稀土锰钙钛矿系统的电阻-温度曲线呈现双峰结构。根据核壳结构,说明钾的挥发及银的添加对稀土锰钙钛矿颗粒的磁性以及系统的传输性质产生了影响。n=4的样品在很宽的温度范围内表现出很大的磁电阻。实验表明:添加适量的银有利于增大多晶材料的磁电阻并且延展其温度范围。The influence of doping Ag and K on the magnetic and electronic transport properties of the mixture system of Ag- （La0.92K0.04MnO3） n was studied. The double peaks structure was found in the temperature dependence of resistance. According to the coreshell theory, it was interpreted as the effect induced by the doping of Ag and volatilization of K upon the magnetic and electronic transport properties of the perovskite manganite granular system. For the sample n = 4, large magnetoresistance effect was observed in a broad temperature range. Studies indicated that the moderate addition of Ag improved the value and extended the effective temperature range of magnetoresistance of polycrystalline materials.

关 键 词：磁电阻 稀土锰钙钛矿 核壳结构 稀土 

分 类 号：TM273[一般工业技术—材料科学与工程]