The Magnetic Dependence of the Debye Temperature of a Ferromagnet

A compact expression is suggested for the description of the magnetic dependence of the Debye temperature $\theta$ of a ferromagnet in the form of expansion in powers of the square of magnetization $M^2$ and "temperature distance" to the Curie point $t = T - T_C$. The approach is illustrated by successive treatment of the thermodynamics of ferromagnet within the conventional theory of Landau phase transitions of the second order, which leads inevitably to the "inclusion" of the magnetic dependence of $\theta$ even in the initial assumption of the absence of magnetic dependence of the characteristic temperature.