Exchange magnetic field torques in YIG/Pt bilayers observed by the spin-Hall magnetoresistance

The effective field torque of an yttrium-iron-garnet (YIG) film on the spin accumulation in an attached platinum (Pt) film is measured by the spin-Hall magnetoresistance (SMR). As a result, the magnetization direction of a ferromagnetic insulating layer can be measured electrically. Experimental transverse and longitudinal resistances are well described by the theoretical model of SMR in terms of the direct and inverse spin-Hall effect, for different Pt thicknesses [3, 4, 8, and 35 nm]. Adopting a spin-Hall angle of Pt theta(SH) = 0.08, we obtain the spin diffusion length of Pt (lambda = 1.1 +/- 0.3 nm) as well as the real (G(r) = (7 +/- 3) x 10(14) Omega (1)m(-2)) and imaginary part (G(i) = (5 +/- 3) x 10(13) Omega (1)m(-2)) of the spin-mixing conductance and their ratio (G(r)/G(i) = 16 +/- 4). (C) 2013 AIP Publishing LLC