The phase stability,magnetic properties,martensitic transformation,and electronic properties of the Ni_(2−x)Mn_(1+x+y)Sn_(1−y) system with excess Mn have been systematically investigated by the first-principles calcul...The phase stability,magnetic properties,martensitic transformation,and electronic properties of the Ni_(2−x)Mn_(1+x+y)Sn_(1−y) system with excess Mn have been systematically investigated by the first-principles calculations.Results indicate that the excess Mn atoms will directly occupy the sublattices of Ni(MnNi)or Sn(MnSn).The formation energy(Ef)of the austenite has a relationship with the Mn content:Ef=135.27(1+x+y)−293.01,that is,the phase stability of the austenite decreases gradually with the increase in Mn content.According to the results of the formation energy of austenite,there is an antiparallel arrangement of the magnetic moment between the excess and normal Mn atoms in the Ni_(2−x)Mn_(1+x+y)Sn_(1−y)(x=0 or y=0)system,while the magnetic moment direction of the normal Mn atoms arranges antiparallel to that of MnNi atoms and parallel to that of MnSn atoms in the Ni_(2−x)Mn_(1+x+y)Sn_(1−y)(x,y≠0)system.The martensitic transformation occurs in some Ni_(2−x)Mn_(1+x+y)Sn_(1−y)(x,y≠0)alloys with large magnetic moments of ferrimagnetic austenite.Besides,the valence electrons tend to distribute around the Ni or MnNi atoms and mainly bond with the normal Mn atoms.The results of this work can lay a theoretical foundation for further development of the Ni_(2−x)Mn_(1+x+y)Sn_(1−y) system as the potential ferromagnetic shape memory alloys.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51771044)the Natural Science Foundation of Hebei Province(No.E2019501061)+2 种基金the Performance subsidy fund for Key Laboratory of Dielectric and Electrolyte Functional Material Hebei(No.22567627H)the Fundamental Research Funds for the Central Universities(No.N2223025)the Programme of Introducing Talents of Discipline Innovation to Universities 2.0(the 111 Project of China 2.0,No.BP0719037)。
文摘The phase stability,magnetic properties,martensitic transformation,and electronic properties of the Ni_(2−x)Mn_(1+x+y)Sn_(1−y) system with excess Mn have been systematically investigated by the first-principles calculations.Results indicate that the excess Mn atoms will directly occupy the sublattices of Ni(MnNi)or Sn(MnSn).The formation energy(Ef)of the austenite has a relationship with the Mn content:Ef=135.27(1+x+y)−293.01,that is,the phase stability of the austenite decreases gradually with the increase in Mn content.According to the results of the formation energy of austenite,there is an antiparallel arrangement of the magnetic moment between the excess and normal Mn atoms in the Ni_(2−x)Mn_(1+x+y)Sn_(1−y)(x=0 or y=0)system,while the magnetic moment direction of the normal Mn atoms arranges antiparallel to that of MnNi atoms and parallel to that of MnSn atoms in the Ni_(2−x)Mn_(1+x+y)Sn_(1−y)(x,y≠0)system.The martensitic transformation occurs in some Ni_(2−x)Mn_(1+x+y)Sn_(1−y)(x,y≠0)alloys with large magnetic moments of ferrimagnetic austenite.Besides,the valence electrons tend to distribute around the Ni or MnNi atoms and mainly bond with the normal Mn atoms.The results of this work can lay a theoretical foundation for further development of the Ni_(2−x)Mn_(1+x+y)Sn_(1−y) system as the potential ferromagnetic shape memory alloys.
