Publication detail
Shear Deformation of Non-modulated Ni2MnGa Martensite: An Ab Initio Study
HECZKO, M. ŠESTÁK, P. SEINER, H. ZELENÝ, M.
English title
Shear Deformation of Non-modulated Ni2MnGa Martensite: An Ab Initio Study
Type
journal article in Web of Science
Language
en
Original abstract
The impact of shear deformation in (101)[101] system of non-modulated (NM) martensite in Ni2MnGa ferromagnetic shape memory alloy is investigated by means of ab initio atomistic simulations. The shear system is associated with twinning of NM lattice and intermatensitic transformation to modulated structures. The stability of the NM lattice increases with increasing content of Mn. The most realistic shear mechanism for twin reorientation can be approximated by the simple shear mechanism, although the lowest barriers were calculated for pure shear mechanism. The energy barrier between twin variants further reduces due to spontaneous appearance of lattice modulation or, in other words, the nanotwins with thickness of two atomic planes. Such nanotwins appear also on the generalized planar fault energy (GPFE) curve calculated using a newly developed advanced procedure and exhibits even lower energy than the defect free NM structure. These nanotwin doublelayers are also basic building blocks of modulated structures and play an important role in intermartensitic transformation.
English abstract
The impact of shear deformation in (101)[101] system of non-modulated (NM) martensite in Ni2MnGa ferromagnetic shape memory alloy is investigated by means of ab initio atomistic simulations. The shear system is associated with twinning of NM lattice and intermatensitic transformation to modulated structures. The stability of the NM lattice increases with increasing content of Mn. The most realistic shear mechanism for twin reorientation can be approximated by the simple shear mechanism, although the lowest barriers were calculated for pure shear mechanism. The energy barrier between twin variants further reduces due to spontaneous appearance of lattice modulation or, in other words, the nanotwins with thickness of two atomic planes. Such nanotwins appear also on the generalized planar fault energy (GPFE) curve calculated using a newly developed advanced procedure and exhibits even lower energy than the defect free NM structure. These nanotwin doublelayers are also basic building blocks of modulated structures and play an important role in intermartensitic transformation.
Keywords in English
NiMnGa; Ferromagnetic shape memory alloy; Martensite; Twinning; Shear deformation; Intermartensitic transformation; Ab initio calculations
Released
07.11.2024
Publisher
SPRINGER INT PUBL AG
Location
CHAM
ISSN
2199-3858
Volume
10
Number
4
Pages from–to
474–486
Pages count
13
BIBTEX
@article{BUT193835,
author="Martin {Heczko} and Petr {Šesták} and Hanuš {Seiner} and Martin {Zelený},
title="Shear Deformation of Non-modulated Ni2MnGa Martensite: An Ab Initio Study",
year="2024",
volume="10",
number="4",
month="November",
pages="474--486",
publisher="SPRINGER INT PUBL AG",
address="CHAM",
issn="2199-3858"
}