Theory of the thermal conductivity of metallic localized spin compounds in a magnetic field

We calculated the influence of a de magnetic field on the thermal conductivity of localized spin metallic systems as a function of temperature. A variational method was used. The influence of the joint impurity and phonon scattering processes together with the localized spin influence is shown. Remarkable features are found at low temperature and near the critical transition. An increase of conductivity with field near T-C is discussed. It is also argued that a coherent effect due to the field is the cause of the thermal conductivity enhancement at low temperature. The magneto-thermal conductivity is shown at different temperatures.