Gd_(0.55)Sr(0.45)MnO_3薄膜光诱导电阻变化特性研究  

Photoinduced change in resistance of charge-ordering Gd_(0.55)Sr_(0.45)MnO_3 thin film

作　　者：赵省贵[1] 金克新[2] 罗炳成[2] 王建元[2] 陈长乐[2] 

机构地区：[1]西安科技大学理学院,西安710054 [2]西北工业大学凝聚态结构与性质陕西省重点实验室,西安710072

出　　处：《物理学报》2012年第4期431-435,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51172183;61078057和50702046);陕西省教育厅科研计划项目(批准号:2010JK673);西北工业大学基础研究基金(批准号:NPU-FFR-JC200821和JC201048);西北工业大学"翱翔之星"项目资助的课题~~

摘　　要：分别采用固相反应和脉冲激光沉积的方法制备了电荷-轨道有序态锰氧化物Gd_(0.55)Sr_(0.45)MnO_3块材和多晶薄膜,研究了薄膜在光诱导作用下的电阻变化特性.实验结果表明该薄膜在整个测量温度范围内表现出了半导体型导电特性.利用变程跳跃模型拟合电阻温度关系可知,其电荷有序态转变温度为70 K.激光作用致使薄膜电阻减小,当激光功率度为40 mW/mm^2时,最大光致电阻相对变化值可达99.8%,且在8 s的时间内达到了平衡态,温度对其影响很小;当激光功率度为6 mW/mm^2时,获得的最大光致电阻相对变化值为44%,而且时间常数随温度的升高而增大,这主要是由于光诱导和热扰动共同作用的结果.The compound and the film of the critical charge-ordering Gd_（0.05）Sr_（0.45）MnO_3 thin film are prepared using the solid state reaction technique and the pulsed laser deposition method respectively.The properties of the photoinduced relative change in the resistance of the film are investigated.Experimental results indicate that the film exhibits the semiconductive conduction and the charge-ordering temperature is about 70 K from the fitting of a variable-range hopping model.The maximum value of the photoinduced relative change in resistance is about 99.8%when the laser with a power density of 40 mW/mm2 irradiates the film,and the rise time is about 8s independent of temperature.The maximum value of the photoinduced relative change in resistance is about 44%at T = 20 K when the laser with a power density of 6 mW/mm2 irradiates the film.The time constant is increased with the increase of temperature,which is attributed to the competition between photoinduced effect and thermal fluctuation.

关 键 词：电荷-轨道有序 输运特性 光诱导作用 

分 类 号：O482.4[理学—固体物理]