Large spin Nernst effect in the N i70 C u30 alloy
Journal
Physical Review B
Journal Volume
111
Journal Issue
5
ISSN
2469-9950
2469-9969
Date Issued
2025-02-13
Author(s)
Abstract
The interplay among heat, spin, and charge is the central focus in spin caloritronic research. While the longitudinal heat-to-spin conversion via the spin Seebeck effect has been intensively studied, the transverse heat-to-spin conversion via the spin Nernst effect (SNE) has not been equally explored. One major challenge is the minuscule signals generated by the SNE, which are often mixed with the background noises. In this work, we overcome this difficulty by studying the thin films of Ni70Cu30 alloy with not only a sizable spin Hall angle but also a large Seebeck coefficient. We observe in the Ni70Cu30 alloy a large spin Nernst effect with an estimated spin Nernst angle (θSN) ranging from -28% to -72%. In comparison, the θSN for Pt is -8.2%. Our ab initio calculation reveals that the large spin Nernst conductivity (αSN) in Ni70Cu30 is caused by the Fermi energy shift to the steepest slope of the spin Hall conductivity curve due to electron doping from 30% Cu. Our study provides critical directions in searching for materials with a large spin Nernst effect.
Publisher
American Physical Society (APS)
Type
journal article