0603249 - ÚT 2025 RIV CH eng J - Journal Article
Heczko, M. - Šesták, P. - Seiner, Hanuš - Zelený, M.
Shear Deformation of Non-modulated Ni2MnGa Martensite: An Ab Initio Study.
Shape Memory and Superelasticity. Roč. 10, č. 4 (2024), s. 474-486. ISSN 2199-384X. E-ISSN 2199-3858
R&D Projects: GA MŠMT(CZ) EH22_008/0004591
Institutional support: RVO:61388998
Keywords : stress-induced martensites * total-energy calculations * twinning stress * magnetic-field * approximation * rearrangement * boundaries * metals * alloys * Ab initio calculations
OECD category: Materials engineering
Impact factor: 2.6, year: 2023
Method of publishing: Open access
Result website:
https://link.springer.com/article/10.1007/s40830-024-00510-zDOI: https://doi.org/10.1007/s40830-024-00510-z

The impact of shear deformation in (101)[101<overline>]\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} gin{document}$$(101)[10\overline{1}]$$\end{document} 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.
Permanent Link: https://hdl.handle.net/11104/0363374