Park B G, Banerjee T, Lodder J C, Jansen R
MESA(+) Institute for Nanotechnology, University of Twente, 7500 AE Enschede, The Netherlands.
Phys Rev Lett. 2006 Sep 29;97(13):137205. doi: 10.1103/PhysRevLett.97.137205. Epub 2006 Sep 28.
The spin asymmetry of elastic and inelastic scattering of nonequilibrium holes injected into Co thin films is examined using a p-type magnetic tunnel transistor. Spin-dependent transmission yields a positive or negative magnetocurrent depending on Co thickness and hole energy. Up to a critical thickness of about 3 nm, (quasi)elastic scattering dominates with a short attenuation length (<1 nm) and preferential attenuation of holes in the majority spin bands, consistent with spin-wave emission. At a larger Co thickness, inelastic scattering dominates with a larger attenuation length ( approximately 4 nm) and opposite spin asymmetry.
