Unidirectional anisotropy in the spin pumping voltage in yttrium iron garnet/platinum bilayers

Detailed measurements of the dc voltage generated in a thin Pt layer deposited on films of yttrium iron garnet (YIG) have been carried out to study the spin pumping effect produced by magnetostatic (MS) modes excited by a microwave field. In relatively thick YIG films the modes are far apart so that one can identify clearly the spin pumping voltage in V-SP produced by each MS mode. We have discovered that when the sputter deposition of the thin Pt layer is made on the YIG film magnetized by a static magnetic field, VSP exhibits a strong unidirectional anisotropy. (C) 2011 American Institute of Physics. [doi:10.1063/1.3631683]