Spin-dependent hot electron transport in Ni₈₁Fe₁₉ and Co₈₄Fe₁₆ films on GaAs(001)

Magnetic tunnel transistors are used to study spin-dependent hot electron transport in ferromagnetic Ni81Fe16 and CO84Fe16 films deposited on GaAs(001). For both Ni81Fe19 and CO84Fe16 the attenuation length of majority electrons is found to decrease with energy, whereas the much smaller attenuation length of minority electrons is found to be nearly constant at electron energies between 1.0 and 1.9 eV above the Fermi level. Contrary to the similarities in the bulk, hot electron scattering at the metal/GaAs interface is found to be much stronger at the Ni18Fe19/GaAs(001) interface than at the CO84Fe16/GaAs(001) interface.