Simultaneous detection of the spin Hall magnetoresistance and Joule heating-induced spin Seebeck effect in Gd3Fe5O12/Pt bilayers

Abstract

Spin Hall magnetoresistance (SMR) provides an effective tool to probe the spin structure in magnet/heavy metal bilayers. Here, we investigate the SMR in Gd3Fe5O12 (GdIG)/Pt bilayers, where GdIG is a compensated ferrimagnetic insulator. Under a finite magnetic field, GdIG has a collinear magnetic phase far away from compensated temperature (Tcomp) and noncollinear/canted magnetic phase around Tcomp of 278 K. A conventional SMR behavior is observed at different temperatures without any sign change around Tcomp. Meanwhile, an asymmetric behavior (unidirectional-like) exists in the observed SMR at the temperatures just above or below Tcomp, because of the contribution of the anisotropic magnetothermopower effect, i.e., spin Seebeck effect. The spin Seebeck effect component exhibits a sign change around Tcomp, which is correlated with the reversal of the sublattice magnetization. Our finding provides an insight into SMR and thermal spin transport in the GdIG/Pt bilayer structure.