摘要
采用溶胶-凝胶法制备了La2/3Ca1/3Mn1-xCuxO3系列样品。实验研究了系列样品的电输运性质、高温导电机制和低场磁电阻效应。结果发现样品高温下导电遵从Mott变程跳跃机制;在0.3 T的磁场下,绝缘体-金属转变附近磁电阻(MR0=[R(H=0)-R(H)]/R(H=0))由没有掺杂时的2％增加到4％Cu掺杂时的80％;实验同时发现与颗粒晶界有关的磁电阻也有实质性的提高。实验结果表明少量的Cu掺杂可以大大提高低场磁电阻效应。
The La2/3Ca,/3Mn1-xCuxO3(0<<<<<<x < 6%) samples were prepared by sol-gel method. Transport properties, conductive mechanism and low-field mag-netoresistance (MR0) were investigated. It is found that conductive mechanism is described by Mott's variable-range hopping and the MRo near the insulator-
metal transition temperature (Tp) increases from 2% to 80% with x from 0 to 4% for a low field of 0.3 T. The experiment also shows that the intergrain magne-toresistance is largely improved. The results indicate that a proper amount of Cu doping can substantially improve magnetoresistance effects.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2004年第4期484-487,共4页
Journal of the Chinese Society of Rare Earths
基金
国家自然科学基金资助项目(10174022)
关键词
凝聚态物理
磁电阻
溶胶-凝胶
CU掺杂
稀土
condensed matter physics
magnetoresistance
sol-gel
Cu doping
rare earths
