Macromagnetic Calculation of the Magnetization of a Deformed Ferromagnet

Abstract

Research has been carried out on the dynamics of magnetization of a deformed ferromagnet in an external ac magnetic field. A microscopic model of a deformed magnetically soft ferromagnet has been suggested, based on the example of an α-iron crystal, which takes into account the Zeeman energy, the energy of interaction with the crystal field, and the magnetic dipole interaction of domains. The parameters of model Hamiltonians agreed with the experimental data on the magnetostriction of iron. Minimization of the functional of the density of the crystal energy by varying the magnetization of the sample made it possible to obtain an expression for the equilibrium magnetization of the ferromagnet in the approximation quadratic in terms of deformation. The numerical solution to the dynamic Bloch equation yielded a solution with the characteristic form of a hysteresis loop, the basic parameters of which depend on the amount of relative deformation of the sample. These numerical results were compared with the experimental data.