Surface sensitivity of the spin Seebeck effect

TL;DR

This study explores how interface quality and surface treatment affect the spin Seebeck effect in YIG-Pt bilayers, revealing that surface strain and anisotropy significantly influence the SSE signal and magnetic properties.

Contribution

It demonstrates that surface treatment alters magnetic anisotropy and SSE magnitude, establishing the SSE as a tool to probe interface magnetic properties.

Findings

Mechanical treatment increases saturation magnetic field H_{sat} from 55.3 mT to 72.8 mT.

Surface strain induces perpendicular magnetic anisotropy.

SSE magnitude is sensitive to interface quality and magnetic anisotropy.

Abstract

We have investigated the influence of the interface quality on the spin Seebeck effect (SSE) of the bilayer system yttrium iron garnet (YIG) - platinum (Pt). The magnitude and shape of the SSE is strongly influenced by mechanical treatment of the YIG single crystal surface. We observe that the saturation magnetic field H_{sat} for the SSE signal increases from 55.3 mT to 72.8 mT with mechanical treatment. The change in the magnitude of H_{sat} can be attributed to the presence of a perpendicular magnetic anisotropy due to the treatment induced surface strain or shape anisotropy in the Pt/YIG system. Our results show that the SSE is a powerful tool to investigate magnetic anisotropy at the interface.