【摘要】 分别采用固相反应技术和脉冲激光沉积的方法制备了La2/3Sr1/3MnO3靶材和薄膜,并研究了磁场、激光和电流等外场诱导下的薄膜电阻变化特性。结果表明,在铁磁金属相,激光辐照诱导薄膜电阻增大,而电流和磁场作用相似,均诱导薄膜电阻减小,这一现象可归结于不同外场通过改变体系中eg电子的自旋状态而影响体系的输运过程,引起电阻的变化。在顺磁绝缘相,利用小极化子模型进行了分析讨论,表明外场诱导电阻减小主要是由于外场作用使小极化子退局域化。更多还原

【Abstract】 The resistance change has been observed in La2/3Sr1/3MnO3 (LSMO) epitaxial thin film induced by the external magnetic, laser, and electric current field respectively. In the ferromagnetic metallic state the increase in resistance of the film induced by laser is attributed to the photoinduced demagnetization of manganites. The reduction in resistance induced by electric field has the same phenomena as the magnetic field effect, which favors the magnetization of the film. In the paramagnetic insulating state the field-induced change in resistance is discussed using the small polaron model. The field-induced effect provides the innovations and is very important to the research and application of the field devices.更多还原