Effects of temperature on the dynamic and static properties of a non-heisenberg anisotropic ferromagnet

In the mean-field approximation, the influence of both temperature and the value of the single-ion anisotropy constant of the “easy axis” type on the phase states and excitation spectra of a non-Heisenberg ferromagnet with S = 1 is studied. The temperature dependences of the vector and tensor order parameters in both the ferromagnetic and nematic phases have been determined. The dependence of excitation spectra on temperature and the value of the anisotropy constant is studied. It is shown that at a temperature different from zero, an additional (non-relaxation) branch of excitations arises in both the ferromagnetic and nematic phases. The temperature dependence of the phase diagram is studied.