Platinum thickness dependence of the inverse spin-Hall voltage from spin pumping in a hybrid yttrium iron garnet/platinum system

We show the experimental observation of the platinum thickness dependence in a hybrid yttrium iron garnet/platinum system of the inverse spin-Hall effect from spin pumping, over a large frequency range and for different radio-frequency powers. From the measurement of the voltage at the resonant condition and the resistance of the normal metal layer, a strong enhancement of the ratio of these quantities has been observed, which is not in agreement with previous studies on the NiFe/platinum system. The origin of this behaviour cannot be fully explained by the spin transport model that we have used and is therefore still unclear. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4754837