Detail publikace

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.

Originální název

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

Typ

článek v časopise ve Web of Science, Jimp

Jazyk

angličtina

Originální abstrakt

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.

Klíčová slova

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

Autoři

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

Vydáno

19. 6. 2021

Nakladatel

Elsevier

Místo

OXFORD

ISSN

0264-1275

Periodikum

Materials & Design

Ročník

209

Číslo

1

Stát

Spojené království Velké Británie a Severního Irska

Strany od

109917

Strany do

-

Strany počet

10

URL

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

Plný text v Digitální knihovně

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