  In the paper a study of a model magnetoelastic solid system is presented. The
system of interest is a mean-field magnet with nearest-neighbour ferromagnetic
interactions and the underlying s.c. crystalline lattice with the long-range
Morse interatomic potential and the anharmonic Debye model for the lattice
vibrations. The influence of the external magnetic field on the thermodynamics
is investigated, with special emphasis put on the consequences of the
magnetoelastic coupling, introduced by the power-law distance dependence of the
magnetic exchange integral. Within the fully self-consistent, Gibbs
energy-based formalism such thermodynamic quantities as the entropy, the
specific heat as well as the lattice and magnetic response functions are
calculated and discussed. To complete the picture, the magnetocaloric effect is
characterized by analysis of the isothermal entropy change and the adiabatic
temperature change in the presence of the external pressure.
