Longitudinal Spin Seebeck Effect Free from the Proximity Nernst Effect

TL;DR

This paper demonstrates that the longitudinal spin Seebeck effect can be observed independently of the proximity Nernst effect, confirming its intrinsic nature in specific material systems through experimental separation techniques.

Contribution

It provides experimental evidence for intrinsic LSSE free from proximity-induced effects, clarifying the origin of observed voltages in spin caloritronic devices.

Findings

LSSE observed in Au/Y3Fe5O12 and Pt/Cu/YIG systems

Proximity ANE effects can be effectively separated from LSSE

Negligible ANE contamination in Pt/YIG structures

Abstract

This letter provides evidence for intrinsic longitudinal spin Seebeck effects (LSSEs) that are free from the anomalous Nernst effect (ANE) caused by an extrinsic proximity effect. We report the observation of LSSEs in Au/Y3Fe5O12 (YIG) and Pt/Cu/YIG systems, showing that LSSE appears even when the mechanism of the proximity ANE is clearly removed. In the conventional Pt/YIG structure, furthermore, we separate the LSSE from the ANE by comparing the voltages in different magnetization and temperature-gradient configurations; the ANE contamination was found to be negligibly small even in the Pt/YIG structure.