Detail publikace

First-principles study of Zn-doping effects on phase stability and magnetic anisotropy of Ni-Mn-Ga alloys

JANOVEC, J. STRAKA, L. SOZINOV, A. HECZKO, O. ZELENÝ, M.

Anglický název

First-principles study of Zn-doping effects on phase stability and magnetic anisotropy of Ni-Mn-Ga alloys

Typ

článek v časopise ve Web of Science, Jimp

Jazyk

en

Originální abstrakt

The effect of Zn doping on Ni-Mn-Ga magnetic shape memory alloy was studied by the first-principles calculations using exact muffin-tin orbital method in combination with the coherent-potential approximation and projector augmented-wave method. Trends in martensitic transformation temperature T-M and Curie temperature T-C were predicted from calculated energy differences between austenite and nonmodulated martensite, Delta EA-NM, and energy differences between paramagnetic and ferromagnetic state, Delta EPM-FM. Doping upon the Ga-sublattice results in stabilization of martensitic phase which indicates the increase in T-M. T-C is affected only weakly or slightly decreases, because Delta EPM-FM of martensite does not change significantly with doping. The substitution of Mn atoms by Zn causes the decrease in both T-M and T-C. Comparing to Cu-doped Ni-Mn-Ga alloys, we predict that doping with Zn results in smaller decrease in T-C but also in smaller increase in T-M. Moreover, Cu doping upon the Ga-sublattice strongly decreases the magnetic anisotropy energy of martensite, whereas such strong effect was not observed for Zn doping. Based on the calculations of Zn-doped Ni-Mn-Ga alloys we suggest that simultaneous doping with Zn and an element increasing T-C can result in significant increase in both transformation temperatures without strong decrease of magnetic anisotropy.

Anglický abstrakt

The effect of Zn doping on Ni-Mn-Ga magnetic shape memory alloy was studied by the first-principles calculations using exact muffin-tin orbital method in combination with the coherent-potential approximation and projector augmented-wave method. Trends in martensitic transformation temperature T-M and Curie temperature T-C were predicted from calculated energy differences between austenite and nonmodulated martensite, Delta EA-NM, and energy differences between paramagnetic and ferromagnetic state, Delta EPM-FM. Doping upon the Ga-sublattice results in stabilization of martensitic phase which indicates the increase in T-M. T-C is affected only weakly or slightly decreases, because Delta EPM-FM of martensite does not change significantly with doping. The substitution of Mn atoms by Zn causes the decrease in both T-M and T-C. Comparing to Cu-doped Ni-Mn-Ga alloys, we predict that doping with Zn results in smaller decrease in T-C but also in smaller increase in T-M. Moreover, Cu doping upon the Ga-sublattice strongly decreases the magnetic anisotropy energy of martensite, whereas such strong effect was not observed for Zn doping. Based on the calculations of Zn-doped Ni-Mn-Ga alloys we suggest that simultaneous doping with Zn and an element increasing T-C can result in significant increase in both transformation temperatures without strong decrease of magnetic anisotropy.

Klíčová slova anglicky

magnetic shape memory alloy; ab initio calculations; doping; phase stability; martensitic transformation; Curie temperature; magnetic anisotropy

Vydáno

04.02.2020

Nakladatel

IOP Publishing

Místo

BRISTOL

ISSN

2053-1591

Ročník

7

Číslo

2

Strany od–do

026101–-

Počet stran

11

BIBTEX


@article{BUT163950,
  author="Jozef {Janovec} and Ladislav {Straka} and Alexei {Sozinov} and Oleg {Heczko} and Martin {Zelený},
  title="First-principles study of Zn-doping effects on phase stability and magnetic anisotropy of Ni-Mn-Ga alloys",
  year="2020",
  volume="7",
  number="2",
  month="February",
  pages="026101---",
  publisher="IOP Publishing",
  address="BRISTOL",
  issn="2053-1591"
}