Optimization of Thermo-Spin Voltage in Vertical Nanostructures by Geometrical Means

The thermo-spin conversion provides new concepts for further developing thegreen energy-harvesting technology because spin can be controlled with minimalenergy in nanostructures. Through theoretical analysis of thermo-spingeneration, transportation and conversion in ferromagnet/non-ferromagnet/heavymetal (FM/NM/HM) vertical structures, we found that the output transversethermo-spin voltage is independent of the structure's width, but varies in alinear function with the structure's length. To validate our predictions, wefabricated the thermo-spin devices with a CoFeAl/Cu/Pt structure. Our resultsindicate that FM/NM/HM structures can be utilized to design flexiblethermo-spin conversion devices.