Surface magnetic anisotropy-mediated spin Hall magnetoresistance and spin Seebeck effects in a YIG/Pt heterostructure

•Spin Seebeck effect (SSE), Spin Hall magnetoresistance (SMR), and transverse susceptibility (TS) have been studied in YIG/Pt system.•A similar temperature dependence with a peak at ∼ 80 K is observed in SSE, SMR, and surface anisotropy field.•The low-temperature behavior of these effects is related to a non-collinear alignment of bulk and surface spin states in YIG.•Temperature, Field, and thickness dependence of the low-temperature peak is explained through surface anisotropy change.