A1 Journal article (refereed), original research

Ab initio prediction of stable nanotwin double layers and 4O structure in Ni2MnGa


LUT Authors / Editors

Publication Details
Authors: Zeleny Martin, Straka Ladislav, Sozinov Alexei, Heczko Oleg
Publication year: 2016
Language: English
Related Journal or Series Information: Physical review B: Condensed matter and materials physics
Volume number: 94
Start page: 1
End page: 6
JUFO-Level of this publication: 2
Open Access: Not an Open Access publication

Abstract
The ab initio electronic structure calculations of the Ni2MnGa alloy indicate that the orthorhombic 4Ostructure exhibits the lowest energy compared to all known martensitic structures. The 4O structure is formed bynanotwin double layers, i.e., oppositely oriented nanotwins consisting of two (101) lattice planes of nonmodulatedmartensitic structure. It exhibits the lowest occupation of density of states at the Fermi level. The total energy1.98 meV/atom below the energy of nonmodulated martensite is achieved within structural relaxation by shiftingMn and Ga atoms at the nanotwin boundaries. The same atomic shift can also be found in other martensiticnanotwinned or modulated structures such as 10M and 14M, which indicates the importance of the nanotwindouble layer for the stability of these structures. Our discovery shows that the nanotwinning or modulation is anatural property of low-temperature martensitic phases in Ni-Mn-Ga alloys.

Last updated on 2018-19-10 at 08:49