Optical determination of spin diffusion length and interfacial spin mixing conductance in epitaxial Pd/Fe bilayers

Abstract

We present a detailed study of the photoinduced magnetization precession and magnetic relaxation in epitaxial Pd/Fe films on MgO(0 0 1) substrates via all-optical pump-probe techniques. We explicitly formulate the correlation between the Gilbert damping and the effective damping in the optical approach. Furthermore, a non-local Gilbert damping induced by spin pumping is demonstrated self-consistently by the Gilbert damping dependence on Pd thickness and the relationship of damping with Fe thickness . The non-local Gilbert damping enables the determination of spin diffusion length in Pd and interfacial spin mixing conductance . Our work paves the way toward the optical determination of spin transport parameters.