Crystal-field effects on the thermal conductivity of localized spin metallic compounds

Influence of crystal field excitations on thermal and electrical resistivity of normal rare‐earth metals

“…In order to take into account the s–f interaction between of the spins of the conduction electrons and the total spin moments of 4f‐shells of RE ions, we treat this interaction by the method described in Refs. . The only difference is that the conduction electrons are assumed to gain or loose the energy of crystal field excitations of RE ion in the course of the scattering event, not the excitations of the magnetic moment below the Curie temperature in a crystal‐field‐free RE ferromagnet like in Ref.…”

“…The only difference is that the conduction electrons are assumed to gain or loose the energy of crystal field excitations of RE ion in the course of the scattering event, not the excitations of the magnetic moment below the Curie temperature in a crystal‐field‐free RE ferromagnet like in Ref. () or fictitious excitations of a two‐level system like in (). For simplicity, we also assume that the system is in paramagnetic state.…”

“…Since the beginning of the intensive studies of rare earth (RE) metals only the simplest models models and approximations have been applied to study the influence of the crystal field and magnetic excitations on the electrical resistivity of normal (or of stable 4f shell) metallic RE compounds. As concerns the theory of the thermal conductance the literature is less numerous and it is controversial . The thermal conductivity was described by using models with two and three scattering sources () but no reference was made to the thermal resistivity, which is known to obey the Matthiessen rule () in case of appropriate model assumptions.…”

“…As concerns the theory of the thermal conductance the literature is less numerous and it is controversial . The thermal conductivity was described by using models with two and three scattering sources () but no reference was made to the thermal resistivity, which is known to obey the Matthiessen rule () in case of appropriate model assumptions. The Matthiessen was applied successfully to study experimental results of the thermal resistivity of normal rare earth (RE) metals of .…”

“…The Matthiessen was applied successfully to study experimental results of the thermal resistivity of normal rare earth (RE) metals of . The results of () occurred to describe correctly the character of the temperature dependence and the order of the magnitude of the thermal conductivity of the compounds though the form of the formula for the thermal conductivity contradicted the validity of the Matthiessen rule. In the present paper, we apply a better approximation () in which this contradiction is removed, demonstrate formulae for the electrical and thermal resistivity following from dipole–dipole s–f interaction in case of a general crystal field splitting and show that these formulae describe well the character and the magnitude of the temperature dependence of both the electrical and thermal resistivity.…”