Magnetism of ordered and disordered Ni2MnAl full Heusler compounds

E. Simon, J. Gy Vida, S. Khmelevskyi, L. Szunyogh

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Based on ab initio calculations and Monte Carlo simulations, we present a systematic study of the magnetic ground state and finite temperature magnetism of ordered and disordered Ni2MnAl full Heusler compounds. By increasing the degree of the long-range chemical disorder between the Mn and Al sublattices, the magnetic order progressively changes from the ferromagnetic state in the ordered L21 phase toward a fully compensated antiferromagnetic state in the disordered B2 phase and we also conclude that the Ni atoms exhibit induced moments. We determine the Mn-Mn interactions by using the magnetic force theorem and find dominating, but rather weak ferromagnetic couplings in the ordered L21 phase. We used a recently proposed renormalization technique to include the weak Ni moments into the spin model, which indeed remarkably increased the nearest-neighbor Mn-Mn interaction. In accordance with the total energy calculations, in the disordered compounds, strong antiferromagnetic site-antisite Mn-Mn interactions appear. Determining the spin-spin correlation functions from Monte Carlo simulations, we conclude that above the transition temperature, short-range antiferromagnetic correlations prevail between the Mn atoms. In view of the potential application of disordered Ni2MnAl as a room temperature antiferromagnet, we calculate the magnetic anisotropy energies of tetragonally distorted samples in the B2 phase and find that they are smaller by two orders in magnitude than in the frustrated antiferromagnet IrMn3.

Original languageEnglish
Article number054438
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume92
Issue number5
DOIs
Publication statusPublished - Aug 28 2015

Fingerprint

Magnetism
Atoms
Magnetic anisotropy
Ground state
Superconducting transition temperature
moments
interactions
Temperature
sublattices
atoms
simulation
theorems
transition temperature
disorders
anisotropy
ground state
energy
room temperature
Monte Carlo simulation
temperature

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

Magnetism of ordered and disordered Ni2MnAl full Heusler compounds. / Simon, E.; Vida, J. Gy; Khmelevskyi, S.; Szunyogh, L.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 92, No. 5, 054438, 28.08.2015.

Research output: Contribution to journalArticle

@article{12967734d88745a68d07dcd946a6102d,
title = "Magnetism of ordered and disordered Ni2MnAl full Heusler compounds",
abstract = "Based on ab initio calculations and Monte Carlo simulations, we present a systematic study of the magnetic ground state and finite temperature magnetism of ordered and disordered Ni2MnAl full Heusler compounds. By increasing the degree of the long-range chemical disorder between the Mn and Al sublattices, the magnetic order progressively changes from the ferromagnetic state in the ordered L21 phase toward a fully compensated antiferromagnetic state in the disordered B2 phase and we also conclude that the Ni atoms exhibit induced moments. We determine the Mn-Mn interactions by using the magnetic force theorem and find dominating, but rather weak ferromagnetic couplings in the ordered L21 phase. We used a recently proposed renormalization technique to include the weak Ni moments into the spin model, which indeed remarkably increased the nearest-neighbor Mn-Mn interaction. In accordance with the total energy calculations, in the disordered compounds, strong antiferromagnetic site-antisite Mn-Mn interactions appear. Determining the spin-spin correlation functions from Monte Carlo simulations, we conclude that above the transition temperature, short-range antiferromagnetic correlations prevail between the Mn atoms. In view of the potential application of disordered Ni2MnAl as a room temperature antiferromagnet, we calculate the magnetic anisotropy energies of tetragonally distorted samples in the B2 phase and find that they are smaller by two orders in magnitude than in the frustrated antiferromagnet IrMn3.",
author = "E. Simon and Vida, {J. Gy} and S. Khmelevskyi and L. Szunyogh",
year = "2015",
month = "8",
day = "28",
doi = "10.1103/PhysRevB.92.054438",
language = "English",
volume = "92",
journal = "Physical Review B-Condensed Matter",
issn = "0163-1829",
publisher = "American Physical Society",
number = "5",

}

TY - JOUR

T1 - Magnetism of ordered and disordered Ni2MnAl full Heusler compounds

AU - Simon, E.

AU - Vida, J. Gy

AU - Khmelevskyi, S.

AU - Szunyogh, L.

PY - 2015/8/28

Y1 - 2015/8/28

N2 - Based on ab initio calculations and Monte Carlo simulations, we present a systematic study of the magnetic ground state and finite temperature magnetism of ordered and disordered Ni2MnAl full Heusler compounds. By increasing the degree of the long-range chemical disorder between the Mn and Al sublattices, the magnetic order progressively changes from the ferromagnetic state in the ordered L21 phase toward a fully compensated antiferromagnetic state in the disordered B2 phase and we also conclude that the Ni atoms exhibit induced moments. We determine the Mn-Mn interactions by using the magnetic force theorem and find dominating, but rather weak ferromagnetic couplings in the ordered L21 phase. We used a recently proposed renormalization technique to include the weak Ni moments into the spin model, which indeed remarkably increased the nearest-neighbor Mn-Mn interaction. In accordance with the total energy calculations, in the disordered compounds, strong antiferromagnetic site-antisite Mn-Mn interactions appear. Determining the spin-spin correlation functions from Monte Carlo simulations, we conclude that above the transition temperature, short-range antiferromagnetic correlations prevail between the Mn atoms. In view of the potential application of disordered Ni2MnAl as a room temperature antiferromagnet, we calculate the magnetic anisotropy energies of tetragonally distorted samples in the B2 phase and find that they are smaller by two orders in magnitude than in the frustrated antiferromagnet IrMn3.

AB - Based on ab initio calculations and Monte Carlo simulations, we present a systematic study of the magnetic ground state and finite temperature magnetism of ordered and disordered Ni2MnAl full Heusler compounds. By increasing the degree of the long-range chemical disorder between the Mn and Al sublattices, the magnetic order progressively changes from the ferromagnetic state in the ordered L21 phase toward a fully compensated antiferromagnetic state in the disordered B2 phase and we also conclude that the Ni atoms exhibit induced moments. We determine the Mn-Mn interactions by using the magnetic force theorem and find dominating, but rather weak ferromagnetic couplings in the ordered L21 phase. We used a recently proposed renormalization technique to include the weak Ni moments into the spin model, which indeed remarkably increased the nearest-neighbor Mn-Mn interaction. In accordance with the total energy calculations, in the disordered compounds, strong antiferromagnetic site-antisite Mn-Mn interactions appear. Determining the spin-spin correlation functions from Monte Carlo simulations, we conclude that above the transition temperature, short-range antiferromagnetic correlations prevail between the Mn atoms. In view of the potential application of disordered Ni2MnAl as a room temperature antiferromagnet, we calculate the magnetic anisotropy energies of tetragonally distorted samples in the B2 phase and find that they are smaller by two orders in magnitude than in the frustrated antiferromagnet IrMn3.

UR - http://www.scopus.com/inward/record.url?scp=84941140423&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84941140423&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.92.054438

DO - 10.1103/PhysRevB.92.054438

M3 - Article

VL - 92

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 0163-1829

IS - 5

M1 - 054438

ER -