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Competition between cubic and tetragonal phasesin all-d-metal Heusler alloys, X2-xMn1+xV (X= Pd, Ni, Pt, Ag, Au, Ir, Co; x= 1, 0): a new potential direction of the Heusler family

Journal Article


Abstract


  • In this work, a series of all-d-metal Heusler alloys, X 2 - x Mn 1 + x V (X = Pd, Ni, Pt, Ag, Au, Ir, Co; x; = 1, 0), were predicted by first principles. The series can be roughly divided into two categories: XMn 2 V (Mn-rich type) and X 2 MnV (Mn-poor type). Using optimized structural analysis, it is shown that the ground state of these all-d-metal Heusler alloys does not fully meet the site-preference rule for classic full-Heusler alloys. All the Mn-rich type alloys tend to form the L2 1 structure, where the two Mn atoms prefer to occupy the A (0, 0, 0) and C (0.5, 0.5, 0.5) Wyckoff sites, whereas for the Mn-poor-type alloys, some are stable with XA structures and some are not. The c/a ratio was also changed while maintaining the volume the same as in the cubic state to investigate the possible tetragonal transformation of these alloys. The Mn-rich Heusler alloys have strong cubic resistance; however, all the Mn-poor alloys prefer to have a tetragonal state instead of a cubic phase through tetragonal transformations. The origin of the tetragonal state and the competition between the cubic and tetragonal phases in Mn-poor alloys are discussed in detail. Results show that broader and shallower density-of-states structures at or in the vicinity of the Fermi level lower the total energy and stabilize the tetragonal phases of X 2 MnV (X = Pd, Ni, Pt, Ag, Au, Ir, Co). Furthermore, the lack of virtual frequency in the phonon spectra confirms the stability of the tetragonal states of these Mn-poor all-d-metal Heusler alloys. This work provides relevant experimental guidance in the search for possible martensitic Heusler alloys in all-d-metal materials with less Mn and new spintronic and magnetic intelligent materials among all-d-metal Heusler alloys.

UOW Authors


  •   Han, Yilin (external author)
  •   Wu, Mengxin (external author)
  •   Feng, Yu (external author)
  •   Cheng, Zhenxiang
  •   Lin, Tingting (external author)
  •   Yang, Tie (external author)
  •   Khenata, Rabah (external author)
  •   Wang, Xiaotian (external author)

Publication Date


  • 2019

Published In


Citation


  • Han, Y., Wu, M., Feng, Y., Cheng, Z., Lin, T., Yang, T., Khenata, R. & Wang, X. (2019). Competition between cubic and tetragonal phasesin all-d-metal Heusler alloys, X2-xMn1+xV (X= Pd, Ni, Pt, Ag, Au, Ir, Co; x= 1, 0): a new potential direction of the Heusler family. IUCrJ, 6 465-472.

Scopus Eid


  • 2-s2.0-85065298232

Number Of Pages


  • 7

Start Page


  • 465

End Page


  • 472

Volume


  • 6

Place Of Publication


  • United Kingdom

Abstract


  • In this work, a series of all-d-metal Heusler alloys, X 2 - x Mn 1 + x V (X = Pd, Ni, Pt, Ag, Au, Ir, Co; x; = 1, 0), were predicted by first principles. The series can be roughly divided into two categories: XMn 2 V (Mn-rich type) and X 2 MnV (Mn-poor type). Using optimized structural analysis, it is shown that the ground state of these all-d-metal Heusler alloys does not fully meet the site-preference rule for classic full-Heusler alloys. All the Mn-rich type alloys tend to form the L2 1 structure, where the two Mn atoms prefer to occupy the A (0, 0, 0) and C (0.5, 0.5, 0.5) Wyckoff sites, whereas for the Mn-poor-type alloys, some are stable with XA structures and some are not. The c/a ratio was also changed while maintaining the volume the same as in the cubic state to investigate the possible tetragonal transformation of these alloys. The Mn-rich Heusler alloys have strong cubic resistance; however, all the Mn-poor alloys prefer to have a tetragonal state instead of a cubic phase through tetragonal transformations. The origin of the tetragonal state and the competition between the cubic and tetragonal phases in Mn-poor alloys are discussed in detail. Results show that broader and shallower density-of-states structures at or in the vicinity of the Fermi level lower the total energy and stabilize the tetragonal phases of X 2 MnV (X = Pd, Ni, Pt, Ag, Au, Ir, Co). Furthermore, the lack of virtual frequency in the phonon spectra confirms the stability of the tetragonal states of these Mn-poor all-d-metal Heusler alloys. This work provides relevant experimental guidance in the search for possible martensitic Heusler alloys in all-d-metal materials with less Mn and new spintronic and magnetic intelligent materials among all-d-metal Heusler alloys.

UOW Authors


  •   Han, Yilin (external author)
  •   Wu, Mengxin (external author)
  •   Feng, Yu (external author)
  •   Cheng, Zhenxiang
  •   Lin, Tingting (external author)
  •   Yang, Tie (external author)
  •   Khenata, Rabah (external author)
  •   Wang, Xiaotian (external author)

Publication Date


  • 2019

Published In


Citation


  • Han, Y., Wu, M., Feng, Y., Cheng, Z., Lin, T., Yang, T., Khenata, R. & Wang, X. (2019). Competition between cubic and tetragonal phasesin all-d-metal Heusler alloys, X2-xMn1+xV (X= Pd, Ni, Pt, Ag, Au, Ir, Co; x= 1, 0): a new potential direction of the Heusler family. IUCrJ, 6 465-472.

Scopus Eid


  • 2-s2.0-85065298232

Number Of Pages


  • 7

Start Page


  • 465

End Page


  • 472

Volume


  • 6

Place Of Publication


  • United Kingdom