Hysteretic structural changes within five-layered modulated 10M martensite of Ni-Mn-Ga(-Fe)

0543045 - FZÚ 2022 RIV GB eng J - Journal Article
Veřtát, Petr - Seiner, Hanuš - Straka, Ladislav - Klicpera, M. - Sozinov, A. - Fabelo, O. - Heczko, Oleg
Hysteretic structural changes within five-layered modulated 10M martensite of Ni-Mn-Ga(-Fe).
Journal of Physics-Condensed Matter. Roč. 33, č. 26 (2021), č. článku 265404. ISSN 0953-8984. E-ISSN 1361-648X
R&D Projects: GA ČR GA19-09882S; GA ČR(CZ) GA20-12624S; GA MŠMT(CZ) EF16_019/0000760
Grant - others:OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Institutional support: RVO:68378271 ; RVO:61388998
Keywords : ferromagnetic shape memory * phase transformations * twinning * microstructure * structural modulation
OECD category: Condensed matter physics (including formerly solid state physics, supercond.); Acoustics (UT-L)
Impact factor: 2.745, year: 2021
Method of publishing: Limited access
https://doi.org/10.1088/1361-648X/abfb8f

Modulated structure of Ni–Mn–Ga-based alloys is decisive in their magnetic shape memory(MSM) functionality. However, the precise nature of their five-layered modulated 10Mmartensite is still an open question. We used x-ray and neutron diffraction experiments onsingle crystals to investigate structural changes within 10M-modulated martensite of theNi50Mn27Ga22Fe1MSM alloy. The modulation vector gradually increases upon cooling fromcommensurateq=(2/5)g110,whereg110is the reciprocal lattice vector, to incommensuratewithqup to pseudo-commensurateq=(3/7)g110. Upon heating, reverse changes areobserved with a thermal hysteresis of≈60 K. The same hysteretic behaviour was detected inthe electrical resistivity and the effective elastic modulus. Scanning electron microscopyshowed that the changes are accompanied by the refinement of thea/blaminate. Theseobservations indicate that the commensurate state is a metastable form of 10M martensite.

Permanent Link: http://hdl.handle.net/11104/0320352