采用磁控溅射方法制备了二价碱土元素微量掺杂锰氧化物La0.85Sr0.015MnO3(LSMO)薄膜。电阻-温度关系表明,薄膜在273K时发生铁磁金属-顺磁半导体相变。在磁场和激光作用下,薄膜呈现出不同的响应特性:在整个测试温度区间内,磁场作用使薄膜电阻变小,在243K时,取得最大磁电阻变化率为21%;激光辐照薄膜在不同的相态显示出不同的变化特性,在铁磁金属态导致电阻增大,而在顺磁半导体态则致使电阻减小。从能带理论的角度定性地分析了产生该现象的原因是外场对eg电子的作用不同。
The thin film of La0.85Sr0.015MnO3 (LSMO) doping a small amount of divalent alkaline earth microelement has been prepared by magnetron sputtering method. A metal ferromagnetic state to-insulator paramagnetic state (M-I) transition at 273 K has been observed according to the resistance-temperature curve of increasing temperature for the film. The film exhibits different response characters in applied magnetic field and laser. The resistance of film decreased in magnetic fields with the maximum variability of 21% at 243 K. The laser induces the resistance increasing in the ferromagnetic state and decreasing in the paramagnetic state. These phenomena are attributed to the effect of applied field on the eg electrons in the terms of energy band theory.