La_(0.85)Li_(0.15)MnO_3薄膜的制备及磁场、激光诱导效应  

Preparation,Magnetic Field and Photo Induced Effects of La_(0.85)Li_(0.15)MnO_3 Film

作　　者：韩立安[1] 朱金山[1] 陈长乐[2] 

机构地区：[1]西安科技大学理学院,陕西西安710054 [2]西北工业大学理学院,陕西西安710072

出　　处：《河北师范大学学报（自然科学版）》2011年第4期358-361,共4页Journal of Hebei Normal University：Natural Science

基　　金：国家自然科学基金(60171034);陕西省教育厅科技专项(2010JK674);西安科技大学博士启动基金(A5031207)

摘　　要：通过直流磁控溅射法在单晶SrTiO3(100)衬底上制备了膜厚约为93.8 nm的La0.85Li0.15MnO3薄膜.用X线衍射仪、直流四探针法对其结构及磁、光诱导效应进行了研究.结果表明,薄膜为赝立方钙钛矿结构,具有良好的(100)取向.260 K时,薄膜发生金属—绝缘体转变.在金属区,激光使薄膜的阻值增大,磁场使薄膜的阻值减小.电输运性质表明,在低温区,电阻满足公式R(T)=R0+R1T2+R2T4.5,此输运机制主要是由电子-电子散射造成的;在高温区,输运特性与小极化子模型R(T)=R0Texp(Ea/KBT)完全吻合,输运机制是由于小极化子近邻跃迁引起的.由于外场诱导使得小极化子退局域,导致小极化子跃迁能减小,所以高温区外场导致样品电阻减小.Using DC magnetron sputtering method,La0.85Li0.15MnO3 thin film with the thickness of 93.8 nm was grown on SrTiO3 single-crystal substrates.The results show that the thin film is a pseudo-cubic perovskite structure and has the well epitaxial direction of（100）.The metal-insulator transform temperature is 260 K.The laser irradiation results in the increment of the resistance,which is due to the photo induced demagnetization effect.However,the magnetic field results in the decrease of the resistance.Transport properties indicate that the resistance satisfies the term of R=R0 ＋R1T2＋R2T4.5 in the lower temperature which is due to electron-electron scattering,the resistance satisfy polarons model R（T）=R0Texp（Ea/KBT） in the higher temperature which is due to the existence of the small polarons nearest hopping.The magnetic and photo induce the decrease in the resistance owing to the field-induced delocalization of the small polarons.

关 键 词：La0.85Li0.15MnO3薄膜 磁场 激光诱导 电输运 

分 类 号：O482.5[理学—固体物理]