Green's functions and the thermodynamic quantities of the Meisenburg model with one-ion anisotropy

The method of solution is developed for the chain of equations for Green functions, which is based on using of the exact kinematical relationships. For the particular case $S=1$ ($S$ being the spin of a single atom) the thermodynamical quantities and the Green function are calculated in a large region of temperature and the correction to the Curie temperature is found. In the case of arbitrary spin $S$ the results for the low temperature region are obtained.