Thermally driven spin and charge currents in thin NiFe2O4/Pt films

TL;DR

This paper reports the first observation of the spin Seebeck effect in NiFe2O4/Pt thin films, analyzing its temperature dependence and distinguishing it from other thermoelectric effects, contributing to spin caloritronics understanding.

Contribution

It presents the first experimental detection of the spin caloric effect in NiFe2O4 thin films and explores its temperature and magnetic field dependencies.

Findings

First observation of spin Seebeck effect in NiFe2O4 films

Temperature dependence of LSSE characterized

Distinction between LSSE and anomalous Nernst effect achieved

Abstract

We present results on the longitudinal spin Seebeck effect (LSSE) shown by semiconducting ferrimagnetic NiFe2O4/Pt films from room temperature down to 50K base temperature. To the best of our knowledge, this is the first observation of spin caloric effect in NiFe2O4 thin films. The temperature dependence of the conductivity has been studied in parallel to obtain information about the origin of the electric potentials detected at the Pt coverage of the ferrimagnet in order to distinguish the LSSE from the anomalous Nernst effect. Furthermore, the dependence of the LSSE on temperature gradients as well as the influence of an external magnetic field direction is investigated.