Spin‐Thermoelectric Generation of Insulator‐Based Generators Incorporating a Single‐Crystal Yttrium Iron Garnet Film in Relation to Domain Magnetization Processes

Abstract

Normalized VSTE–H loops measured for generators fabricated from LPE‐grown yttrium iron garnet Y3–xBixFe5O12 (YIG/Bi:YIG) films agree well with the normalized M–H curves observed for those films by using a vibrating sample magnetometer. VSTE and M are the spin‐thermoelectric (STE) voltage and the YIG/Bi:YIG magnetization depending on an external field H, respectively. The coincidence between VSTE–H loops and M–H curves indicates that VSTE strongly depends on the magnetic property of ferrimagnetic insulator YIG films incorporated in STE generators. We try explaining the STE generation with VSTE–H loops from a viewpoint of domain magnetization processes in single‐crystal YIG/Bi:YIG films grown by liquid phase epitaxy (LPE). We exemplify that our idea about the fundamental mechanism of STE generation in an insulator‐based generator also well explains the mode of spin waves generated under a temperature gradient ∇T parallel to a plane of Pt/YIG bilayer interface. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.