Anomalous and Planar Nernst effects in thin-films of half-metallic ferromagnet La2/3Sr1/3MnO3

TL;DR

This paper investigates the planar and anomalous Nernst effects in thin films of La2/3Sr1/3MnO3, revealing high sensitivity to thermal gradients and clarifying the nature of magneto-thermoelectric signals in this material.

Contribution

It provides the first detailed analysis of Nernst effects in La2/3Sr1/3MnO3 thin films, highlighting their sensitivity to thermal gradients and distinguishing these effects from the Spin Seebeck Effect.

Findings

Large asymmetric voltages due to parasitic thermal gradients.

Anomalous Nernst effect is highly sensitive to small temperature differences.

Magneto-thermoelectric signals are not consistent with Spin Seebeck Effect.

Abstract

We report the planar and anomalous Nernst effect in epitaxial thin films of spin polarized La2/3Sr1/3MnO3. The thermal counterpart of the anomalous Hall effect in this material (i.e. the anomalous Nernst effect) shows a extreme sensitivity to any parasitic thermal gradient, resulting in large asymmetric voltages under small temperature differences. This should be considered when interpreting the magnitude of the electrical response in nanostructures and devices that operate under high current densities. Finally, none of the observed magneto-thermoelectric signals is compatible with the observation of the Spin Seebeck Effect in this material.