Magnetoresistance measurements on Fe/Si and Fe/Ge multilayer thin films

The magnetoresistance and magnetization of multilayer Fe/Si and Fe/Ge films on GaAs were measured simultaneously as a function of magnetic field along the in-plane [110] and [11¯0] directions of the Fe. The field induced changes in the magnetoresistance and magnetization for each film are discussed in terms of the exchange coupling between the iron layers, and the thickness of the semiconductor spacer layer. The data show that there is exchange coupling across Ge spacer layers for layer thickness less than 1.2 nm.