Extraordinary magnetic and structural properties of the off-stoichiometric and the Co-doped Ni.sub.2./sub.MnGa Heusler alloys under high pressure

0435763 - FZÚ 2015 RIV GB eng J - Journal Article
Kamarád, Jiří - Albertini, F. - Arnold, Zdeněk - Fabbrici, S. - Kaštil, Jiří
Extraordinary magnetic and structural properties of the off-stoichiometric and the Co-doped Ni₂MnGa Heusler alloys under high pressure.
Acta Materialia. Roč. 77, Sep (2014), s. 60-67. ISSN 1359-6454. E-ISSN 1873-2453
R&D Projects: GA ČR GAP204/12/0692
Institutional support: RVO:68378271
Keywords : Heusler alloys * martensitic transformation * magnetic properties * high pressure
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 4.465, year: 2014

To show and to describe a contrast between the magnetic and structural properties of the stoichiometric Ni2MnGa alloy and the off-stoichiometric and the Co-doped Ni–Mn–Ga alloys, we report the effect of high hydrostatic pressure (up to 1.2 GPa) on magnetization and the critical temperatures of structural and magnetic transitions in the off-stoichiometric Ni50−xMn25+x+yGa25−y and the Co-doped Ni50−xCoxMn25+yGa25−y Heusler alloys. A huge decrease in their saturation magnetization MM(5 K) under pressure was observed with an extreme value of pressure parameter d ln MM(5 K)/dP = −56 × 10−3 GPa−1 in the case of the Ni39Co11Mn34Ga16 alloy. The Curie temperature TCA increases under pressure in all the studied alloys. Almost identical values of dTCA/dP = +4.7 ÷ +5.9 K GPa−1 point to a normalized steepness of a dependence of exchange interactions on interatomic distances.
Permanent Link: http://hdl.handle.net/11104/0239576