Temperature dependence of twinning and magnetic stresses in Ni.sub.46./sub.Mn.sub.24./sub.Ga.sub.22./sub.Co.sub.4./sub.Cu.sub.4./sub. alloy with giant 12% magnetic field-induced strain

0478806 - FZÚ 2018 RIV US eng J - Journal Article
Sozinov, A. - Soroka, A. - Lanska, N. - Rameš, Michal - Straka, Ladislav - Ullakko, K.
Temperature dependence of twinning and magnetic stresses in Ni₄₆Mn₂₄Ga₂₂Co₄Cu₄ alloy with giant 12% magnetic field-induced strain.
Scripta Materialia. Roč. 131, Apr (2017), s. 33-36. ISSN 1359-6462. E-ISSN 1872-8456
R&D Projects: GA ČR GA16-00043S
Institutional support: RVO:68378271
Keywords : Heusler phases * ferromagnetic shape memory alloy * twinning * magnetic anisotropy * magnetic shape memory
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 4.163, year: 2017

We study magnetic shape memory alloy Ni46Mn24Ga22Co4Cu4 showing up to 12% magnetic field-induced strain (MFIS). The MFIS is mediated by motion of the compound twin boundaries (CTBs) in non-modulated tetragonal crystal lattice. We present temperature dependences of the twinning stress σTW(T), tetragonality ratio, and magnetic anisotropy energy density KU(T), used for magnetic stress σMAG(T) calculations. With temperature increasing, the twinning stress for CTBs decreases with the slope of ‐0.02 MPa/K, twice slower than observed for type I twin boundaries in 10M Ni-Mn-Ga martensite. We found and explained existence of temperature window, within which the giant MFIS is observed.
Permanent Link: http://hdl.handle.net/11104/0274874