Abstract
Polarized neutron and X-ray reflectivity are complementary tools for measuring the magnetic depth profile of a thin film. In this experiment, permalloy (Ni 80 Fe 20 , 30 nm) thin film was deposited on Al 2 O 3 (1 1̄ 0 0) substrates with Co(8 nm)/Mo(18 nm) as buffer layers. The depth profile between the permalloy and Co cannot be determined by X-ray reflectivity alone because the electron densities are too close together. Polarized neutron reflectivity, although available only with limited q range available, can determine the interface roughness between the permalloy and Co layer.