Abstract

The effect of hydrogen absorption on the magnetooptical (MO) properties of Fe/Pd and Co/Pd bilayers was investigated. It was observed that there were no changes either in the magnetic response or in the optical reflectivity in the Co/Pd bilayers, with thickness similar to the Fe/Pd sample, due to Co interdiffusion with the Pd layer. A lack of H2 absorption was also observed in a Pd membrane with only 5% Ru, resulting from the transition metal diffusing to the surface of the alloy, and inhibiting absorption due to the fundamental changes in the band structure that could modify the chemisorption properties. The possibility of using the optical response of the samples to measure hydrogen pressure was also discussed.