An Ab Initio Study of Pressure-Induced Changes of Magnetism\nin Austenitic Stoichiometric Ni2MnSn

0538851 - ÚFM 2022 RIV CH eng J - Journal Article
Friák, Martin - Mazalová, Martina - Turek, Ilja - Zemanová, Adéla - Kaštil, Jiří - Kamarád, Jiří - Míšek, Martin - Arnold, Zdeněk - Schneeweiss, Oldřich - Všianská, Monika - Zelený, M. - Kroupa, Aleš - Pavlů, J. - Šob, Mojmír
An Ab Initio Study of Pressure-Induced Changes of Magnetism
in Austenitic Stoichiometric Ni2MnSn.
Materials. Roč. 14, č. 3 (2021), č. článku 523. E-ISSN 1996-1944
R&D Projects: GA MŠMT(CZ) LM2018096; GA ČR(CZ) GA20-16130S
Institutional support: RVO:68081723 ; RVO:68378271
Keywords : Ni-Mn-Sn * alloys * pressure * magnetism * ab initio * stability * point defects * swaps
OECD category: Pure mathematics; Condensed matter physics (including formerly solid state physics, supercond.) (FZU-D)
Impact factor: 3.748, year: 2021
Method of publishing: Open access
https://www.mdpi.com/1996-1944/14/3/523

We have performed a quantum-mechanical study of a series of stoichiometric Ni2MnSn
structures focusing on pressure-induced changes in their magnetic properties. Motivated by the facts
that (i) our calculations give the total magnetic moment of the defect-free stoichiometric Ni2MnSn
higher than our experimental value by 12.8% and (ii) the magnetic state is predicted to be more
sensitive to hydrostatic pressures than seen in our measurements, our study focused on the role of
point defects, in particular Mn-Ni, Mn-Sn and Ni-Sn swaps in the stoichiometric Ni2MnSn. For most
defect types we also compared states with both ferromagnetic (FM) and anti-ferromagnetic (AFM)
coupling between (i) the swapped Mn atoms and (ii) those on the Mn sublattice. Our calculations
show that the swapped Mn atoms can lead to magnetic moments nearly twice smaller than those in
the defect-free Ni2MnSn. Further, the defect-containing states exhibit pressure-induced changes up
to three times larger but also smaller than those in the defect-free Ni2MnSn. Importantly, we find
both qualitative and quantitative differences in the pressure-induced changes of magnetic moments
of individual atoms even for the same global magnetic state. Lastly, despite of the fact that the
FM-coupled and AFM-coupled states have often very similar formation energies (the differences
only amount to a few meV per atom), their structural and magnetic properties can be very different.
Permanent Link: http://hdl.handle.net/11104/0322648