  In recent years, multifunctional materials have attracted increasing interest
for magnetic memories and energy harvesting applications. Magnetic insulating
materials are of special interest for this purpose, since they allow the design
of more efficient devices due to the lower Joule heat losses. In this context,
Ga$_{0.6}$Fe$_{1.4}$O$_3$ (GFO) is a good candidate for spintronics
applications, since it can exhibit multiferroicity and presents a spin Hall
magnetoresistance similar to the one observed in a yttrium iron garnet (YIG)/Pt
bilayer. Here, we explore GFO utilizing thermo-spin measurements in an on-chip
approach. By carefully considering the geometry of our thermo-spin devices we
are able to quantify the spin Seebeck effect and the spin current generation in
a GFO/Pt bilayer, obtaining a value comparable to that of YIG/Pt. This further
confirms the promises of an efficient spin current generation with the
possibility of an electric-field manipulation of the magnetic properties of the
system in an insulating ferrimagnetic material.
