The impact of magnetoelasticity on structural phase transitions in cubic ferromagnets
نویسندگان
چکیده
Influence of the magnetoelastic interaction on the structural phase transitions in cubic ferromagnets is investigated on the basis of a Ginzburg-Landau theory. It is shown that for the case of a positive magnetic anisotropy constant the structural phase transitions are not accompanied by a spin-reorientation. In the magnetic state the high-temperature phase has small deformations caused by the magnetostriction. For the case of a strong magnetoelastic coupling these deformations lead to vanishing of the first order structural transitions. Corresponding critical points are determined. Due to the magnetoelastic interaction a first order magnetic phase transition can occur simultaneously with a structural first order transformation. The constrained theory allows to calculate a realistic (T,x)-phase diagram for Ni2+xMn1−xGa alloys. 64.10.+h, 64.70.Kb, 75.30.Gw, 75.80.+q Typeset using REVTEX 1
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