  We examine the influence of crystal growth on the spin-pumping induced
inverse spin Hall effect in Fe/Pt bilayers. The morphology of the Fe/Pt
interface influences the effective spin mixing conductance. The increase of
growth temperature leads to smoother and larger grains at the interface that
enhance the effective spin mixing conductance. The spin current injection
efficiency into Pt, measured by the inverse spin Hall effect, is maximized by
optimizing the epitaxy of Pt on Fe. In magnetic field dependent measurements,
the presence of a strong magnetic anisotropy gives rise to two distinct inverse
spin Hall effect voltage peaks.
