Enhancement of anomalous Nernst effect in Ni/Pt superlattice

TL;DR

This study demonstrates a significant enhancement of the anomalous Nernst effect in Ni/Pt superlattices, with increased Nernst coefficients linked to large transverse Peltier effects, surpassing bulk Ni performance.

Contribution

It reports the first observation of enhanced ANE in Ni/Pt superlattices and identifies the large transverse Peltier coefficient as the key factor.

Findings

Nernst coefficient increased to over 1 μV/K for 2-4 nm Ni layers

Large transverse Peltier coefficient (α_xy) observed, reaching 4.8 A/K·m for 4 nm Ni

Enhanced ANE surpasses bulk Ni performance

Abstract

We report an enhancement of the anomalous Nernst effect (ANE) in Ni/Pt (001) epitaxial superlattices. The transport and magneto-thermoelectric properties were investigated for the Ni/Pt superlattices with various Ni layer thicknesses (${\it t}$). The anomalous Nernst coefficient was increased up to more than 1 ${\mu}$V K$^{-1}$ for 2.0 nm ${\leq}$ ${\it t}$ ${\leq}$ 4.0 nm, which was the remarkable enhancement compared to the bulk Ni. It has been found that the large transverse Peltier coefficient (${\alpha}$$_{xy}$), reaching ${\alpha}$$_{xy}$ = 4.8 A K$^{-1}$ m$^{-1}$ for ${\it t}$ = 4.0 nm, plays a prime role for the enhanced ANE of the Ni/Pt (001) superlattices.