La_(2/3)Sr_(1/3)MnO_3/BaTiO_3复合薄膜的制备及其电致磁电效应研究  

Preparation and electric field driven magnetoelectric effect for multiferroic La_(2/3)Sr_(1/3)MnO_3/BaTiO_3 composite films

作　　者：李廷先[1] 张铭[1] 王光明[1] 郭宏瑞[1] 李扩社[2] 严辉[1] 

机构地区：[1]北京工业大学材料科学与工程学院,北京100124 [2]北京有色金属研究总院稀土材料国家工程研究中心,北京100088

出　　处：《物理学报》2011年第8期645-649,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51002013);北京市教育委员会科研计划(批准号:KM200910005023)资助的课题~~

摘　　要：使用脉冲激光沉积技术,在LaAlO3(001)单晶基片上制备了La2/3Sr1/3MnO3(LSMO)/BaTiO3(BTO)双层薄膜.X射线衍射分析显示,LSMO层和BTO层呈现纯(001)取向.原子力显微镜研究表明,薄膜表面晶粒大小均匀,排列致密,表面均方根粗糙度为1.4nm.复合薄膜的磁学、电学性能研究表明,其具有良好的磁学和介电性能.电输运测试显示,与在BTO层上施加正方向直流电压相比,当在BTO层上施加负方向直流电压时,LSMO表面层的电阻率变低,金属绝缘体相变温度TMI变高,亦即引起了LSMO层磁性的变化.这表明LSMO中磁学序参量和BTO中的电学序参量之间存在着耦合,即发生了由直流电场诱发的电致磁电效应.Using pulsed laser deposition,multiferroic La2/3Sr1/3MnO3（LSMO）/BaTiO3（BTO） composite films are deposited on LaAlO3 （LAO）（001） substrate.X-ray diffraction results show that LSMO and BTO films exhibit only （001） orientation.Film smoothness is verified by their low root-mean-square surface roughness values as 1.4 nm from atomic force microscope study.The magnetic and the electric properties of these composite films are investigated.Furthermore,the variations of resistivity and metal-insulator transition temperature TMI of LSMO,induced by the external electric field,are studied.The resisitivity is reduced while the TMI is enhanced for hole accumulation state which is induced by negative electric field across BTO layer.In contrast,the resistivity is enhanced while the TMI is reduced for hole depletion state,which shows coupling between magnetic and electric order parameters,i.e.,there is a magnetoelectric effect induced by electric field.

关 键 词：磁电效应 铁电/铁磁异质结构 脉冲激光沉积 

分 类 号：O484[理学—固体物理]