On the interfacial thermal conductance of a ferromagnetic metal junction

Abstract

We follow the conventional two-channel resistor model to describe the spin transport through an F|N (ferromagnetic metal|normal metal) interface in the field of spin caloritronics and its relationship with the interfacial thermal conductance. We show that the interfacial thermal conductance not only depends on terms of Fourier conduction transport, but also on interfacial parameters, such as electrical resistance, the Seebeck coefficient and the temperature gradient. The new term, which includes these parameters, is called the spin thermoelectric term of the interfacial thermal conductance and shows that when the system is excited by small fluctuations of temperature at the interface, permanently-induced currents are produced, resulting in nonzero values, as a first insight into the total thermal conductance magnitude order. Moreover, the relationship between this spin thermoelectric term and the applied charge current can be linearly approximated in the range of zero to the applied compensation current Ip under the effect of Peltier cooling. In general, the thermal conductance capacity can be drastically improved at nanoscale.