中文摘要：

利用脉冲激光沉积的方法,在Nb-1wt%：SrTiO3基片上分别生长了5nm和50nm的La0.67Ca0.33MnO3薄膜得到异质结.对该异质结电流-电压特性和磁阻的研究表明,50nm厚的样品表现出良好的整流特性并且在外加1T磁场的情况下无明显变化,而5nm厚的样品在低温下,整流特性发生变化,并且外加1T磁场对其整流特性有明显影响,显示负的磁阻.通过考虑p-n结耗尽层的厚度,对观察到的实验现象进行了解释.

英文摘要：

The p - n junctions were fabricated by developing La0.67Ca0.33MnO3 thin films with thicknesses of 5 nm and 50 nm respectively on Nb-1 wt% ：SrTiO3 through the method of using pulsed laser deposition. The current-voltage （I-V） measurements show that the sample with 50 nm thick film displays a good rectifying property, and no changes were observed under an applied magnetic field of IT. But the rectifying property of the sample with 5 nm thick film nearly disappeared under low temperature and the electrical characteristics can be remarkably influenced by applied 1T magnetic field. The magnetoresistance of the sample with 5 nm thick film can reached about - 30% at 30K. The results were explained by considering the thicknesses of both the film and the depletion layer in the p - n junctions.