  By means of a mean-field model extended to include magnetovolumic effects we
study the effect of external fields on the thermal response characterized
either by the isothermal entropy change and/or the adiabatic temperature
change. The model includes two different situations induced by the
magnetovolumic coupling. (i) A first order para- ferromagnetic phase transition
that entails a volume change. (ii) An inversion of the effective exchange
interaction that promotes the occurrence of an antiferromagnetic phase at low
temperatures. In both cases, we study the magneto- and baro-caloric effects as
well as the corresponding cross caloric responses. By comparing the present
theoretical results with available experimental data for several materials we
conclude that the present thermodynamical model reproduces the general trends
associated with the considered caloric and cross caloric responses.
