The composition dependence of the crystal structure and magnetism of the 6 M martensite for the Cu-doped Ni43.75Mn37.5In12.5C06.25 alloy at different site occupations(Cu substitution for Ni,Mn,In,and Co,respectively)is investi-gated in detail with the first-principles calculations.Results show that the austenite(A)phase exhibits a ferromagnetic(FM)state in all occupation manners,the 6 M martensite possesses an FM state except for the case of Cu substitution at the normal Mn(Mn1)site,and the non-modulated(NM)martensite displays a ferrimagnetic(FIM)state apart from the Cu substitu-tion at the Ni,Mn1,or In sites.The Cu atom destabilizes the A,6 M,and NM phases regardless of the occupation manner.The one-step martensitic transformation from the A to NM phase occurs in the case of Cu substituting for Mn1,excess Mn(Mn2),or Co;for Cu substituting Ni,a martensitic transformation including 6 M martensite happens,i.e.,A→6 M→NM;however,the martensitic transformation disappears when Cu replaces In site.From the equilibrium lattice constants,it can be speculated that the substitution of Cu for Ni can effectively reduce the thermal hysteresis(△THys).The magnetic properties are found to be greatly reduced by the substitution of the non-magnetic element Cu for the ferromagnetic Mn atom,whereas the effect is fewer in the remaining cases.It is predicted that the alloy has more favorable properties when Cu replaces Ni.The present results can lay a theoretical foundation for further development of multielement magnetic shape memory alloys.

Xinzeng Liang;Jing Bai;Jianglong Gu;Ziqi Guan;Haile Yan;Yudong Zhang;Claude Esling;Xiang Zhao;Liang Zuo

Key Laboratory for Anisotropy and Texture of Materials,Northeastern University,110819 Shenyang,China;School of Resources and Materials,Northeastern University At Qinhuangdao,066004 Qinhuangdao,China;Hebei Provincial Laboratory for Dielectric and Electrolyte Functional Materials,066004 Qinhuangdao,China;State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,066004 Qinhuangdao,China;Laboratoire D'étude Des Microstructures Et de Mécanique Des Matériaux,UMR 7239,LEM3 CNRS,University of Lorraine,57045 Metz,France

金属学报（英文版）

[1]Xinzeng Liang;Jing Bai;Jianglong Gu;Ziqi Guan;Haile Yan;Yudong Zhang;Claude Esling;Xiang Zhao;Liang Zuo-.Composition-Dependent of 6 M Martensite Structure and Magnetism in Cu-Alloyed Ni-Mn-In-Co by First-Principles Calculations)[J].金属学报（英文版）,2022(06):1034-1042

Martensite,Ni43,75Mn37,5In12,5C06,occupations,substitu,destabilizes,THys,multielement

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