Anomalous Nernst effect in compensated ferrimagnetic CoxGd1-x films

TL;DR

This paper reports a significant anomalous Nernst effect in compensated ferrimagnetic CoxGd1-x films, driven by Co-dominant Berry curvature, challenging conventional understanding and opening new avenues for thermoelectric applications.

Contribution

It reveals the presence of a large ANE in compensated ferrimagnets and links it to Co-dominant Berry curvature, providing new insights into thermoelectric phenomena in such materials.

Findings

ANE signal is significant in CoxGd1-x films with near-zero net magnetization.

Polarity of ANE is governed by Co sublattice magnetization, not net magnetization.

The origin of ANE is attributed to Co-dominant Berry curvature.

Abstract

The anomalous Nernst effect (ANE) is one of the most intriguing thermoelectric phenomena which has attracted growing interest both for its underlying physics and potential applications. Typically, a large ANE response is observed in magnets with pronounced magnetizations or nontrivial Berry curvature. Here, we report a significant ANE signal in compensated ferrimagnetic CoxGd1-x alloy films, which exhibit vanishingly small magnetization. In particular, we found that the polarity of ANE signal is dominated by the magnetization orientation of the transition metal Co sublattices, rather than the net magnetization of CoxGd1-x films. This observation is not expected from the conventional understanding of ANE but is analogous to the anomalous Hall effect in compensated ferrimagnets. We attribute the origin of ANE and its Co-dominant property to the Co-dominant Berry curvature. Our work could trigger a more comprehensive understanding of ANE and may be useful for building energy-harvesting devices by employing ANE in compensated ferrimagnets.