高阻相对La2／3Ca1／3MnO3低场磁电阻效应的影响

Effect of High Resistivity Phase on Low-Field Magnetoresistance of La2/3Ca1/3MnO3

摘要:

实验研究了La2／3Ca1/3MnO3系统晶界上掺杂(YSZ)对其输运性能和磁电阻效应(MR)的影响。样品是由溶胶．凝胶法制成的。通过对样品的电输运特性的测量表明，在掺杂量(x)低于2％时，掺杂引起电阻的增大并降低了金属．绝缘体转变温度；当掺杂量高于2％时电阻逐渐减小，且转变温度增加。而低场磁电阻效应随掺杂量增加，在x=1％时达到最大。

Abstract:

The effect of YSZ doping level on transport properties and magnetoresistance in La2/3Ca1/3MnO3 has been experimentally studied. The samples are prepared by a standard sol-gel method. Through the measurement of the electronic properties of samples we can draw a conclusion that for x < 2%, the dopant cause the metal-insulator transition shift to low temperature and increase the resistance of samples. Then with the increase of doping level further, the resistance decreases and the metal-insulator transition temperature increase. Meanwhile , the YSZ dopant can increase the LFMR, it's maximum at 1%.