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

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 backward difference T parallel to a plane of Pt/YIG bilayer interface. (c) 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.