Inverse-Heusler合金Ti_(2)NiAl/MgO(100)异质结的结构、磁性以及电子性质  

Structure,magnetism,and electronic properties of inverse Heusler alloy Ti_(2)NiAl/MgO(100) herterojuction

作　　者：张远强 杨昆 黄海深 吴波 ZHANG Yuan-Qiang;YANG Kun;HUANG Hai-Shen;WU Bo(School of Physics and Electronic Science,Zunyi Normal University,Zunyi 563006,China;School of Physics,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]遵义师范学院物理与电子科学学院,遵义563006 [2]北京理工大学物理学院,北京100081

出　　处：《原子与分子物理学报》2021年第1期130-136,共7页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(11304410);贵州省科技厅联合基金项目(黔科合LH字[2015] 7020号);贵州省教育厅青年项目(黔教合KY字[2018] 310);贵州省洁净能原材料与技术重点实验室(黔教合KY字[2019] 055)。

摘　　要：本文通过第一原理计算,研究了Ti_(2)NiAl/MgO(100)异质结Ti Al-O、TiNi-Mg、TiNi-O和Ti AlMg这4种原子端面的界面结构、原子磁性、态密度和自旋极化.在平衡界面结构中,由于原子间相互作用力的存在,Ti-Mg (Ni-Mg)键的长度远大于Ti-O (Ni-O)键的长度.在所有端面中,原来块体出现的半金属间隙都遭受了界面态的不同程度破坏.在Ti_(2)Ni Al/MgO(100)异质结中,TiNi-O界面检测到具有最大76%左右自旋极化率,根据Julliere模型预测Ti_(2)NiAl/MgO(100)异质结在低温下的隧道磁电阻值(TMR)可以达到281%.The interface structures,atomic magnetism,density of states,and spin polarization of TiAl-O,TiNi-Mg,TiNi-O,and TiAl-Mg atomic terminations in the Ti_(2)NiAl/MgO(100) heterojunction are investigated by the first-principles calculation. In the equilibrium interface structures,the length of Ti-Mg(Ni-Mg)bond is much longer than that of Ti-O(Ni-O) bond due to the interaction between atoms. In all terminations,he half-metallic gap in the bulk phase is destroyed by the surface states. In the TiNi-O termination,the maximum spin polarizability is about 76%. According to the Julliere model,the tunnel magnetoresistance value of about 281% in the Ti_(2)NiAl/MgO(100) heterojunction at low temperature is predicted.

关 键 词：异质结 界面结构 HEUSLER合金 自旋极化 磁性 

分 类 号：O469[理学—凝聚态物理]