Polarized neutron reflectivity of dilute magnetic semiconductors

We report on a polarized neutron reflectivity investigation of the magnetization in Ge-based dilute magnetic semiconductors. We could observe a net magnetization from the splitting of the non-spin flip reflectivity patterns, which measure the magnetic moment parallel and antiparallel to the applied field. This contrast is visible at 50 K, at remanence and it is pronounced at higher fields even at 250 K for an inhomogeneous specimen. For a homogeneous sample the magnetic variation is visible only at 50 K and above 1.0 kOe. Thus, polarized neutron reflectivity can be a useful tool for investigating the magnetism in homogeneous and inhomogeneous thin film magnetic semiconductors.