Comparison of magnetocurrent and transfer ratio in magnetic tunnel transistors with spin-valve bases containing Cu and Au spacer layers

The magnetocurrent of magnetic tunnel transistors with spin-valve base structures is found to be nearly insensitive to whether the spacer layer material in the spin valve is Cu or Au. By contrast, the in-plane magnetoresistance of the same spin valves differs by almost a factor of two. Furthermore, the transfer ratio of the transistor structure is an order of magnitude lower for Au compared to Cu spacer layers. We attribute these different behaviors to the significant role of spin-dependent interface scattering for electrons near the Fermi energy but to much weaker such scattering for hot electrons in the energy range considered (∼1–2 eV).