The modeling of phase diagrams and premartensitic effects in Heusler Ni–Mn–Ga alloy by Monte Carlo method

In this work the coupled magnetostructural and premartensitic phase transitions in Heusler Ni–Mn–Ga alloy have been modeled by Monte Carlo method using Ising and Blume–Emery–Griffiths models. The phase diagrams in coordinates (Temperature–Magnetoelastic constant) were obtained. For the first time it is shown that the magnetoelastic interaction account in austenitic and martensitic phases allows to describe the coupled magnetostructural phase transition in Ni-Mn-Ga alloys. The area of the premartensitic phase transition in the temperature–magnetoelastic constant diagram has been found.