CaIrO_3薄膜中的八面体扭转及金属绝缘转变  

The Octahedral Distorsion and Metal-Insulator Transition in CaIrO_3 Film

作　　者：韩雨 郭状 吴文彬[1] HAN Yu;GUO Zhuang;WU Wenbin(Hefei National Laboratory for Physical Sciences at the Microscals , University of Science and Technology of China, 230026, Hefe)

机构地区：[1]合肥微尺度物质科学国家研究中心中国科学技术大学,合肥230026

出　　处：《低温物理学报》2018年第1期6-11,共6页Low Temperature Physical Letters

基　　金：国家自然科学基金项目(批准号:11474263;11574324;U1432251)资助的课题~~

摘　　要：本文采用激光脉冲沉积(pulsed laser deposition,PLD)方法在NdGaO3(110)(NGO)和(LaAlO_3)_(0.3)(Sr_2AlTaO_6)_(0.7)(001)(LSAT)衬底上生长了厚度变化的钙钛矿结构CaIrO3(CIO)单晶薄膜.在这一体系中,我们观测到了金属绝缘转变现象以及各向异性电输运行为,并且尝试利用应变弛豫调节铱氧八面体绕[100]轴的扭转角度,改变金属绝缘转变温度(TMI).八面体的扭转角度在30nm厚的样品中取得了最大值,同时CIO的TMI取得了最小值.我们推测是八面体的扭转影响了CIO薄膜的带隙宽度,从而造成了TMI的变化以及各向异性电输运行为.The peroviskite CaIrO3（CIO）monocrystalline films with variational thickness have been deposited on NdGaO3（110）（NGO）and（LaAlO3）0.3（Sr2AlTaO6）0.7（001）（LSAT）substrates by the pulsed laser deposition（PLD）technique.In this system, we observe the metal-insulator transition and the anisotropic electrical conductivity.The metal-insulator transition temperature of the CIO films can be changed by the rotation angle of the iridium oxide octahedron around[100]axis with strain relaxation.The rotation angle gets maximum in the film of 30 nm,and the transition temperature reached minimum in the same sample.We believe that the octahedron rotation can adjust the forbidden band width of the CIO thin films,causing the changed temperature and anisotropy of the metal-insulator transition.

关 键 词：5d电子金属氧化物薄膜 金属绝缘转变 八面体扭转 

分 类 号：O484[理学—固体物理]