Spin Seebeck effect in the multifunctional ferrimagnet Ga_0.6Fe_1.4O₃

Thermo-spin current generation in Ga_0.6Fe_1.4O₃ (GFO)/Pt are shown. The spin Seebeck performance of this system is comparable with the widely used yttrium iron garnet, likewise to what we have observed in spin Hall magnetoresistance. We also rule out the possibility of a dominant proximity effect in the thermo-spin voltage by exploring the different magnetoresistive effects in the bilayer¹. In addition, by fabrication of thermo-spin devices with controlled dimensions, we are able to accurately quantify the relevant parameters of the thermal effects, obtaining more accurate and comparable values for the spin Seebeck coefficient².

These results pave the way for the use of the magnetoelectric multiferroic GFO for energy harvesting and with a view to controlling the spin current production of NM/FMI (non-magnetic/ ferromagnetic insulator) heterostructures by an electric field.

1. Homkar, S. et al. Spin Current Transport in Hybrid Pt / Multifunctional Magnetoelectric Ga0.6Fe1.4O3 Bilayers. ACS Appl. Electron. Mater. (2021) https://doi.org/10.1021/acsaelm.1c00586

2. Anadón, A. et al. Spin Seebeck in the multifunctional ferrimagnet Ga0.6Fe1.4O3 (in preparation)