Ideal superelasticity in Ni-based Heusler alloys

The hysteresis that occurs during superelasticity caused by the stress-induced first-order martensite transformation is sometimes detrimental to properties of superelastic materials. In this paper, first-principles calculations are performed systematically investigate effects chemical composition and crystal disorder on Ni50-xCoxM25Ga25 (M = Mn, Fe) Heusler alloys. Calculations stress-strain relation in studied alloys reproduce recent experimental findings for nonhysteretic within an acceptable range ordering. We evaluate Bloch spectral function study Fermi surface topology connection with superelasticity. propose Landau-de Gennes model-dependent critical parameter Pc, which can be used predict For ferromagnetic L21 Ni50-xCoxMn25Ga25 B2 Ni50-xCoxFe25Ga25 alloys, phenomenon theoretically Co contents over x 16 at.% 28 at.%, respectively.