稀土掺杂锰氧化物的电致电阻效应

Electroresistance effect in Sr-doped manganite perovskites

用固相烧结法制备Nd0.67Sr0.33MnOy（y=2.85）多晶样品。样品输运性质表现出自旋相关电致电阻特征。对含量低于化学计量y=3.0样品，当温度高于某一特征温度时，电阻变化符合线性欧姆定律；但低于这一特征温度时，电阻大小与负载电流或电压有关，I-V曲线偏离线性规律；在绝缘体．导体相转变点附近，样品电阻随负载电流或电压增大而迅速减小，表现出巨大电致电阻效应。这种自旋相关的电致电阻行为与氧含量和界面有很大关系。

Spin-dependent electroresistance （ER） effect was found in polycrystalline Nd0.67Sr0.33MnOy（y=2.85） sample, which were synthesized using solid-state reaction method. For Nd0.67Sr0.33MnOy（y=2.85） sample with oxygen-deficient, I-V characteristic is linear when temperature is above a certain point. However, below the critical temperature, electrical resistance strongly depends on load current or voltage and decreases remarkably with increasing the load. The spin-dependent ER effect was explained based on the oxygen-deficient and grain boundary.