中国物理B ›› 2021, Vol. 30 ›› Issue (8): 83103-083103.doi: 10.1088/1674-1056/ac0a6a

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Density functional theory investigation on lattice dynamics, elastic properties and origin of vanished magnetism in Heusler compounds CoMnVZ (Z= Al, Ga)

Guijiang Li(李贵江)1,†, Enke Liu(刘恩克)2,3, Guodong Liu(刘国栋)4, Wenhong Wang(王文洪)2,3, and Guangheng Wu(吴光恒)2   

  1. 1 College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, China;
    2 State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    3 Songshan Lake Materials Laboratory, Dongguan 523808, China;
    4 School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, China
  • 收稿日期:2021-05-20 修回日期:2021-06-08 接受日期:2021-06-11 出版日期:2021-07-16 发布日期:2021-08-13
  • 通讯作者: Guijiang Li E-mail:guijiangli@njtech.edu.cn
  • 基金资助:
    Project supported by Special Fund for Introduced Talent to Initiate Scientific Research in Nanjing Tech University and the National Natural Science Foundation of China (Grant Nos. 51831003 and 51771225).

Density functional theory investigation on lattice dynamics, elastic properties and origin of vanished magnetism in Heusler compounds CoMnVZ (Z= Al, Ga)

Guijiang Li(李贵江)1,†, Enke Liu(刘恩克)2,3, Guodong Liu(刘国栋)4, Wenhong Wang(王文洪)2,3, and Guangheng Wu(吴光恒)2   

  1. 1 College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, China;
    2 State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    3 Songshan Lake Materials Laboratory, Dongguan 523808, China;
    4 School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, China
  • Received:2021-05-20 Revised:2021-06-08 Accepted:2021-06-11 Online:2021-07-16 Published:2021-08-13
  • Contact: Guijiang Li E-mail:guijiangli@njtech.edu.cn
  • Supported by:
    Project supported by Special Fund for Introduced Talent to Initiate Scientific Research in Nanjing Tech University and the National Natural Science Foundation of China (Grant Nos. 51831003 and 51771225).

摘要: The lattice dynamics, elastic properties and the origin of vanished magnetism in equiatomic quaternary Heusler compounds CoMnVZ (Z=Al, Ga) are investigated by first principle calculations in this work. Due to the similar constituent atoms in CoMnVAl and CoMnVGa compounds, they are both stable in LiMgPdSn-type structure with comparable lattice size, phonon dispersions and electronic structures. Comparatively, we find that CoMnVAl is more structurally stable than CoMnVGa. Meanwhile, the increased covalent bonding component in CoMnVAl enhances its mechanical strength and Vickers hardness, which leads to better comprehensive mechanical properties than those of CoMnVGa. Practically and importantly, structural and chemical compatibilities at the interface make non-magnetic semiconductor CoMnVAl and magnetic topological semimetals Co2MnAl/Ga more suitable to be grown in heterostructures. Owing to atomic preferential occupation in CoMnVAl/Ga, the localized atoms Mn occupy C (0.5, 0.5, 0.5) Wyckoff site rather than B (0.25, 0.25, 0.25) and D (0.75, 0.75, 0.75) Wyckoff sites in LiMgPdSn-type structure, which results in symmetric band filling and consequently drives them to be non-magnetic. Correspondingly, by tuning localized atoms Mn to occupy B (0.25, 0.25, 0.25) or/and D (0.75, 0.75, 0.75) Wyckoff sites in off-stoichiometric Co-Mn-V-Al/Ga compounds and keeping the total valence electrons as 24, newly compensated ferrimagnetic compounds are theoretically achieved. We hope that our work will provide more choices for spintronic applications.

关键词: Heusler compounds CoMnVAl/Ga, first principles calculations, lattice dynamics, elastic properties, nonmagnetic semiconductor

Abstract: The lattice dynamics, elastic properties and the origin of vanished magnetism in equiatomic quaternary Heusler compounds CoMnVZ (Z=Al, Ga) are investigated by first principle calculations in this work. Due to the similar constituent atoms in CoMnVAl and CoMnVGa compounds, they are both stable in LiMgPdSn-type structure with comparable lattice size, phonon dispersions and electronic structures. Comparatively, we find that CoMnVAl is more structurally stable than CoMnVGa. Meanwhile, the increased covalent bonding component in CoMnVAl enhances its mechanical strength and Vickers hardness, which leads to better comprehensive mechanical properties than those of CoMnVGa. Practically and importantly, structural and chemical compatibilities at the interface make non-magnetic semiconductor CoMnVAl and magnetic topological semimetals Co2MnAl/Ga more suitable to be grown in heterostructures. Owing to atomic preferential occupation in CoMnVAl/Ga, the localized atoms Mn occupy C (0.5, 0.5, 0.5) Wyckoff site rather than B (0.25, 0.25, 0.25) and D (0.75, 0.75, 0.75) Wyckoff sites in LiMgPdSn-type structure, which results in symmetric band filling and consequently drives them to be non-magnetic. Correspondingly, by tuning localized atoms Mn to occupy B (0.25, 0.25, 0.25) or/and D (0.75, 0.75, 0.75) Wyckoff sites in off-stoichiometric Co-Mn-V-Al/Ga compounds and keeping the total valence electrons as 24, newly compensated ferrimagnetic compounds are theoretically achieved. We hope that our work will provide more choices for spintronic applications.

Key words: Heusler compounds CoMnVAl/Ga, first principles calculations, lattice dynamics, elastic properties, nonmagnetic semiconductor

中图分类号:  (Ab initio calculations)

  • 31.15.A-
75.20.Hr (Local moment in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions) 62.20.-x (Mechanical properties of solids) 63.20.dk (First-principles theory)