中国物理B ›› 2018, Vol. 27 ›› Issue (1): 17502-017502.doi: 10.1088/1674-1056/27/1/017502

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Strong anti-strain capacity of CoFeB/MgO interface on electronic structure and state coupling

Fei Guo(郭飞), Yaping Wu(吴雅苹), Zhiming Wu(吴志明), Ting Chen(陈婷), Heng Li(李恒), Chunmiao Zhang(张纯淼), Mingming Fu(付明明), Yihong Lu(卢奕宏), Junyong Kang(康俊勇)   

  1. Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Fujian Provincial Key Laboratory of Semiconductors and Applications, Department of Physics, Xiamen University, Xiamen 361005, China
  • 收稿日期:2017-05-08 修回日期:2017-08-09 出版日期:2018-01-05 发布日期:2018-01-05
  • 通讯作者: Yaping Wu, Zhiming Wu, Junyong Kang E-mail:ypwu@xmu.edu.cn;zmwu@xmu.edu.cn;jykang@xmu.edu.cn
  • 基金资助:
    Project supported by the National Key Research and Development Program of China (Grant No. 2016YFB0400801), the National Natural Science Foundation of China (Grant Nos. 61774128, 61674124, 11604275, 11304257, and 61227009), the Natural Science Foundation of Fujian Province of China (Grant Nos. 2017J01012, 2014J01026, 2016J01037, and 2015J01028), and the Fundamental Research Funds for the Central Universities, China (Grant Nos. 20720150027, 20720160044, 20720160122, 20720170085,20720170012, and 20720150033).

Strong anti-strain capacity of CoFeB/MgO interface on electronic structure and state coupling

Fei Guo(郭飞), Yaping Wu(吴雅苹), Zhiming Wu(吴志明), Ting Chen(陈婷), Heng Li(李恒), Chunmiao Zhang(张纯淼), Mingming Fu(付明明), Yihong Lu(卢奕宏), Junyong Kang(康俊勇)   

  1. Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Fujian Provincial Key Laboratory of Semiconductors and Applications, Department of Physics, Xiamen University, Xiamen 361005, China
  • Received:2017-05-08 Revised:2017-08-09 Online:2018-01-05 Published:2018-01-05
  • Contact: Yaping Wu, Zhiming Wu, Junyong Kang E-mail:ypwu@xmu.edu.cn;zmwu@xmu.edu.cn;jykang@xmu.edu.cn
  • Supported by:
    Project supported by the National Key Research and Development Program of China (Grant No. 2016YFB0400801), the National Natural Science Foundation of China (Grant Nos. 61774128, 61674124, 11604275, 11304257, and 61227009), the Natural Science Foundation of Fujian Province of China (Grant Nos. 2017J01012, 2014J01026, 2016J01037, and 2015J01028), and the Fundamental Research Funds for the Central Universities, China (Grant Nos. 20720150027, 20720160044, 20720160122, 20720170085,20720170012, and 20720150033).

摘要: Electronic structure and spin-related state coupling at ferromagnetic material (FM)/MgO (FM=Fe, CoFe, CoFeB) interfaces under biaxial strain are evaluated using the first-principles calculations. The CoFeB/MgO interface, which is superior to the Fe/MgO and CoFe/MgO interfaces, can markedly maintain stable and effective coupling channels for majority-spin 1 state under large biaxial strain. Bonding interactions between Fe, Co, and B atoms and the electron transfer between Bloch states are responsible for the redistribution of the majority-spin 1 state, directly influencing the coupling effect for the strained interfaces. Layer-projected wave function of the majority-spin 1 state suggests slower decay rate and more stable transport property in the CoFeB/MgO interface, which is expected to maintain a higher tunneling magnetoresistance (TMR) value under large biaxial strain. This work reveals the internal mechanism for the state coupling at strained FM/MgO interfaces. This study may provide some references to the design and manufacturing of magnetic tunnel junctions with high tunneling magnetoresistance effect.

关键词: ferromagnet material/MgO interface, biaxial strain, state coupling, first-principles calculation

Abstract: Electronic structure and spin-related state coupling at ferromagnetic material (FM)/MgO (FM=Fe, CoFe, CoFeB) interfaces under biaxial strain are evaluated using the first-principles calculations. The CoFeB/MgO interface, which is superior to the Fe/MgO and CoFe/MgO interfaces, can markedly maintain stable and effective coupling channels for majority-spin 1 state under large biaxial strain. Bonding interactions between Fe, Co, and B atoms and the electron transfer between Bloch states are responsible for the redistribution of the majority-spin 1 state, directly influencing the coupling effect for the strained interfaces. Layer-projected wave function of the majority-spin 1 state suggests slower decay rate and more stable transport property in the CoFeB/MgO interface, which is expected to maintain a higher tunneling magnetoresistance (TMR) value under large biaxial strain. This work reveals the internal mechanism for the state coupling at strained FM/MgO interfaces. This study may provide some references to the design and manufacturing of magnetic tunnel junctions with high tunneling magnetoresistance effect.

Key words: ferromagnet material/MgO interface, biaxial strain, state coupling, first-principles calculation

中图分类号:  (Magnetic properties of interfaces (multilayers, superlattices, heterostructures))

  • 75.70.Cn
72.25.Mk (Spin transport through interfaces) 72.25.-b (Spin polarized transport) 73.20.-r (Electron states at surfaces and interfaces)