Generation of dc voltages by a magnetic multilayer undergoing ferromagnetic resonance

We predict that a de voltage V appears across a magnetic multilayer undergoing ferromagnetic resonance. The voltage exists along a direction perpendicular to the layer plane. This is the magnetic analog of a photovoltaic cell. We calculate the rate of spin flip of conduction-electron spins, induced by the precession of the magnetization. Also, we solve the Valet-Fert spin-diffusion equation in the various layers. The de voltage V is obtained by combining these two equations. For sufficiently large precession amplitude, V converges toward a fixed value of order similar or equal to h omega/e similar or equal to 10 mu V, where omega is the angular frequency of precession and e the electron charge. [S0163-1829(99)04517-8].