Janus monolayer TaNF:A new ferrovalley material with large valley splitting and tunable magnetic properties  

作　　者：郑贵博 蘧水仙 周文哲 欧阳方平 Guibo Zheng;Shuixian Qu;Wenzhe Zhou;Fangping Ouyang(School of Physics and Electronics,and Hunan Key Laboratory for Super-Microstructure and Ultrafast Process,and Hunan Key Laboratory of Nanophotonics and Devices,Central South University,Changsha 410083,China;School of Physics and Technology,Xinjiang University,Urumqi 830046,China;State Key Laboratory of Powder Metallurgy,and Powder Metallurgy Research Institute,Central South University,Changsha 410083,China)

机构地区：[1]School of Physics and Electronics,and Hunan Key Laboratory for Super-Microstructure and Ultrafast Process,and Hunan Key Laboratory of Nanophotonics and Devices,Central South University,Changsha 410083,China [2]School of Physics and Technology,Xinjiang University,Urumqi 830046,China [3]State Key Laboratory of Powder Metallurgy,and Powder Metallurgy Research Institute,Central South University,Changsha 410083,China

出　　处：《Frontiers of physics》2023年第5期173-181,共9页物理学前沿（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.52073308 and 11804395);the Distinguished Young Scholar Foundation of Hunan Province(Grant No.2015JJ1020);the Central South University Research Fund for Innovation-driven program(Grant No.2015CXS1035);the Central South University Research Fund for Sheng-hua Scholars(Grant No.502033019);China Postdoctoral Science Foundation(Grant No.2022TQ0379);the State Key Laboratory of Powder Metallurgy at Central South University,and the Fundamental Research Funds for the Central Universities of Central South University.

摘　　要：Materials with large intrinsic valley splitting and high Curie temperature are a huge advantage for studying valleytronics and practical applications.In this work,using first-principles calculations,a new Janus TaNF monolayer is predicted to exhibit excellent piezoelectric properties and intrinsic valley splitting,resulting from the spontaneous spin polarization,the spatial inversion symmetry breaking and strong spin-orbit coupling(SOC).TaNF is also a potential two-dimensional(2D)magnetic material due to its high Curie temperature and large magnetic anisotropy energy.The effective control of the band gap of TaNF can be achieved by biaxial strain,which can transform TaNF monolayer from semiconductor to semi-metal.The magnitude of valley splitting at the CBM can be effectively tuned by biaxial strain due to the changes of orbital composition at the valleys.The magnetic anisotropy energy(MAE)can be manipulated by changing the energy and occupation(unoccupation)states of d orbital compositions through biaxial strain.In addition,Curie temperature reaches 373 K under only−3%biaxial strain,indicating that Janus TaNF monolayer can be used at high temperatures for spintronic and valleytronic devices.

关 键 词：JANUS valley splitting Curie temperature magnetic anisotropy energy first-principles calculations 

分 类 号：O469[理学—凝聚态物理]