中文摘要：

研究了在不同电流下多晶La0.67Ca0.33MnO3薄膜的电输运特性．观察到电阻随着电流的增大而减小，在多晶样品中当外加电流为1mA时负的电电阻（ER）即达到30％．同时，电流对于磁阻（舰）也有影响．考虑多晶样品中晶界的作用，我们提出了极化电流传输模型，对所观察到的实验现象进行了解释。

英文摘要：

The electronic transport behavior of La0. 67Ca0. 33MNO3 polycrystaUine thin films has been investigated under various applied currents. The electric resistance was decreasing with increasing electric current, and ER can reach 30% with a 1 mA current. The electric current can also change the magnetoresistance of the films. Considering the effect of grain boundary, a spin polarized current model has been proposed to explain the results.