  The utilization of ferromagnetic (FM) materials in thermoelectric devices
allows one to have a simpler structure and/or independent control of electric
and thermal conductivities, which may further remove obstacles for this
technology to be realized. The thermoelectricity in FM/non-magnet (NM)
heterostructures using an optical heating source is studied as a function of NM
materials and a number of multilayers. It is observed that the overall
thermoelectric signal in those structures which is contributed by spin Seebeck
effect and anomalous Nernst effect (ANE) is enhanced by a proper selection of
NM materials with a spin Hall angle that matches to the sign of the ANE.
Moreover, by an increase of the number of multilayer, the thermoelectric
voltage is enlarged further and the device resistance is reduced,
simultaneously. The experimental observation of the improvement of
thermoelectric properties may pave the way for the realization of magnetic-(or
spin-) based thermoelectric devices.
