Thermodynamical properties of one-dimensional Heisenberg ferromagnets with static domain wall-like solitons in external magnetic field

Abstract

The perturbation method was used to obtain the contributions to the free energy, specific heat, magnetic susceptibility and correlation functions, caused by external magnetic field applied to one-dimensional, classical Heisenberg ferromagnets with a special uniaxial anisotropy. A transfer integral method was used to obtain the partition function of the system. The validity of calculations is limited to the region of low temperatures and magnetic fields small enough. The results can be understood on the ground of the phenomenological theory of gas of static domain wall-like solitons.