  We compare thermal-gradient-driven transverse voltages in
ferrimagnetic-insulator/heavy-metal bilayers (Tm3Fe5O12/W and Tm3Fe5O12/Pt) to
corresponding electrically-driven transverse resistances at and above room
temperature. We find for Tm3Fe5O12/W that the thermal and electrical effects
can be explained by a common spin-current detection mechanism, the physics
underlying spin Hall magnetoresistance (SMR). However, for Tm3Fe5O12/Pt the
ratio of the electrically-driven transverse voltages (planar Hall
signal/anomalous Hall signal) is much larger than the ratio of corresponding
thermal-gradient signals, a result which is very different from expectations
for a SMR-based mechanism alone. We ascribe this difference to a
proximity-induced magnetic layer at the Tm3Fe5O12/Pt interface.
