Low-temperature heat capacity and magnetization of ferromagnets

The change in the magnetization of a ferromagnet due to disordering in the system of atomic magnetic moments with increasing temperature is put in correspondence with the change in the entropy of the magnetic subsystem. A relationship is obtained for calculating the magnetic component of the heat capacity of the ferromagnet, which satisfactorily describes the temperature dependence of the heat capacity for Fe, Co, TbB₂, and DyB₂ at low temperatures.