Hot-electron transport through Ni₈₀Fe₂₀ in a spin-valve transistor

Hot-electron transport in Ni80Fe20 thin films was studied using a spin-valve transistor. By varying the NiFe thickness from 10 to 100 Å we obtain an attenuation length of 43 Å for majority-spin hot electrons at 0.9 eV above the Fermi level. Based on such relatively long bulk attentuation lengths, one would expect a current transfer ratio that is much larger than the measured value. We propose that the discrepancy can be accounted for by considering interfacial scattering. Increasing the growth quality should thus provide a means to improve the current transfer ratio.