Publication detail

Effect of electron localization in theoretical design of Ni-Mn-Ga based magnetic shape memory alloys

ZELENÝ, M. SEDLÁK, P. HECZKO, O. SEINER, H. VEŘTÁT, P. OBATA, M. KOTANI, T. ODA, T. STRAKA, L.

Original Title

Effect of electron localization in theoretical design of Ni-Mn-Ga based magnetic shape memory alloys

Type

journal article in Web of Science

Language

English

Original Abstract

The precise determination of the stability of different martensitic phases is an essential task in the successful design of (magnetic) shape memory alloys. We evaluate the effect of electron delocalization correction on the predictive power of density functional theory for Ni-Mn-Ga, the prototype magnetic shape memory compound. Using the corrected Hubbard-model-based generalized gradient approximation (GGA+U), we varied the Coulomb repulsion parameter U from 0 eV to 3 eV to reveal the evolution of predicted material parameters. The increasing localization on Mn sites results in the increasing stabilization of 10M modulated structure in stoichiometric Ni2MnGa in agreement with experiment whereas uncorrected GGA and meta-GGA functional provide the lowest energy for 4O modulated structure and nonmodulated structure, respectively. GGA+U calculations indicate that 10M structure is more stable than other martensitic structures for U > 1.2 eV. The key features of density of states (DOS) responsible for the stabilization or destabilization of particular martensitic phases calculated with GGA+U are found also in DOS calculated with advanced quasi-particle self-consistent GW (QSGW) method. It supports the physical background of Hubbard correction. Moreover, the calculations with U = 1.8 eV provide the best agreement with experimental data for lattice parameters of stoichiometric and off-stoichiometric alloys. (C) 2021 The Authors. Published by Elsevier Ltd.

Keywords

Martensitic transformation; Magnetic shape memory alloys; Phase stability; Electron localization; Ab initio calculations; Exchange-correlation energy

Authors

ZELENÝ, M.; SEDLÁK, P.; HECZKO, O.; SEINER, H.; VEŘTÁT, P.; OBATA, M.; KOTANI, T.; ODA, T.; STRAKA, L.

Released

19. 6. 2021

Publisher

Elsevier

Location

OXFORD

ISBN

0264-1275

Periodical

Materials & Design

Year of study

209

Number

1

State

United Kingdom of Great Britain and Northern Ireland

Pages from

109917

Pages to

-

Pages count

10

URL

https://www.sciencedirect.com/science/article/pii/S0264127521004706

Full text in the Digital Library

http://hdl.handle.net/11012/203217