Proposal for in situ Enhancement of Electron Spin Polarization in   Semiconductors
  An extension of the original Overhauser effect to a more general nonequilibrium state was proposed by G. Feher, and demonstrated by Clark and Feher some forty years ago. It is suggested here that it might be possible to produce excess electron spin polarization by allowing the role of the nuclei to be played by other magnetic entities, such as paramagnetic impurities or adjacent magnetically ordered structures. 
Harry Suhl