  Transverse magneto-thermoelectric effects are studied in permalloy thin films
grown on MgO and GaAs substrates and compared to those grown on suspended SiN
membranes. The transverse voltage along platinum strips patterned on top of the
permalloy films is measured vs. the external magnetic field as a function of
angle and temperature gradient. After the identification of the contribution of
the planar and anomalous Nernst effects, we find an upper limit for the
transverse spin Seebeck effect, which is several orders of magnitude smaller
than previously reported.
