Spin battery operated by ferromagnetic resonance
  Precessing ferromagnets are predicted to inject a spin current into adjacent conductors via Ohmic contacts, irrespective of a conductance mismatch with, for example, doped semiconductors. This opens the way to create a pure spin source spin battery by the ferromagnetic resonance. We estimate the spin current and spin bias for different material combinations. 
Arne Brataas, Yaroslav Tserkovnyak, Gerrit E. W. Bauer, and Bertrand   I. Halperin