Kinetics and relaxation processes in Ni-Mn-Ga alloys under an external stress and a magnetic field.

The kinetics of magnetic and structural domains and relaxation of magnetization and strain under an external stress and a magnetic field in ferromagnetic Ni-Mn-Ga alloys close to a structural phase transition on the basis of time-depending Ginzburg-Landau equation with a thermal noise were theoretically investigated. The influence of an external magnetic field on the kinetics of structural domains was established to have the same influence as the stress has but not so great. The evolution of structural domain pictures was obtained. One type of structural domains was established to prevail in an alloy under an external stress or a magnetic field with time. The time dependencies of magnetization and strain were calculated. [ABSTRACT FROM AUTHOR]