Off-axis electron holography of manganite-based heterojunctions:Interface potential and charge distribution  

作　　者：Zhi-Bin Ling Gui-Ju Liu Cheng-Peng Yang Wen-Shuang Liang Yi-Qian Wang 令志斌;刘桂菊;杨成鹏;梁文双;王乙潜(College of Physics & State Key Laboratory, Qingdao University)

机构地区：[1]College of Physics & State Key Laboratory, Qingdao University

出　　处：《Chinese Physics B》2019年第4期269-274,共6页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.10974105);the High-end Foreign Experts Recruitment Programs,China(Grant Nos.GDW20173500154 and GDW20163500110);the Taishan Scholar Program of Shandong Province;Shandong Province "Double–Hundred Talent Plan" on 100 Foreign Experts and 100 Foreign Expert Teams Introduction Project;the Top-notch Innovative Talent Program of Qingdao City,China(Grant No.13-CX-08);the Qingdao International Center for Semiconductor Photoelectric Nanomaterials,and Shandong Provincial University Key Laboratory of Optoelectrical Material Physics and Devices

摘　　要：The interfacial electrical potentials and charge distributions of two manganite-based heterojunctions, i.e.,La_(0.67)Ca_(0.33)MnO_3/SrTiO_3:0.05 wt% Nb(LCMO/STON) and La_(0.67)Ca_(0.33)MnO_3/LaMnO_3/SrTiO_3:0.05 wt% Nb(simplified as LCMO/LMO/STON), are studied by means of off-axis electron holography in a transmission electron microscope.The influences of buffer layer on the microstructure and magnetic properties of the LCMO films are explored. The results show that when a buffer layer of LaMnO_3 is introduced, the tensile strain between the STON substrate and LCMO film reduces, misfit dislocation density decreases near the interfaces of the heterojunctions, and a positive magnetoresistance is observed. For the LCMO/STON junction, positive and negative charges accumulate near the interface between the substrate and the film. For the LCMO/LMO/STON junction, a complex charge distribution takes place across the interface, where notable negative charges accumulate. The difference between the charge distributions near the interface may shed light on the observed generation of positive magnetoresistance in the junction with a buffer layer.The interfacial electrical potentials and charge distributions of two manganite-based heterojunctions, i.e.,La_(0.67)Ca_(0.33)MnO_3/SrTiO_3:0.05 wt% Nb(LCMO/STON) and La_(0.67)Ca_(0.33)MnO_3/LaMnO_3/SrTiO_3:0.05 wt% Nb(simplified as LCMO/LMO/STON), are studied by means of off-axis electron holography in a transmission electron microscope.The influences of buffer layer on the microstructure and magnetic properties of the LCMO films are explored. The results show that when a buffer layer of LaMnO_3 is introduced, the tensile strain between the STON substrate and LCMO film reduces, misfit dislocation density decreases near the interfaces of the heterojunctions, and a positive magnetoresistance is observed. For the LCMO/STON junction, positive and negative charges accumulate near the interface between the substrate and the film. For the LCMO/LMO/STON junction, a complex charge distribution takes place across the interface, where notable negative charges accumulate. The difference between the charge distributions near the interface may shed light on the observed generation of positive magnetoresistance in the junction with a buffer layer.

关 键 词：LA0.67CA0.33MNO3 films electron HOLOGRAPHY magnetic properties INTERFACIAL electrical POTENTIAL charge distribution 

分 类 号：O4[理学—物理]