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 cond uctivity of localized spin metallic systems as a function of temperatu re. A variational method was used. The influence of the joint impurity and phonon scattering processes together with the localized spin infl uence is shown. Remarkable features are found at low temperature and n ear the critical transition. An increase of conductivity with field ne ar T-C is discussed. It is also argued that a coherent effect due to t he field is the cause of the thermal conductivity enhancement at low t emperature. The magneto-thermal conductivity is shown at different tem peratures.