Desorption of Hydrogen from SmH_3-δFilms: Effect of Palladium Overlayer Thickness

Abstract

Desorption of hydrogen from palladium-capped SmH3-δ films of 55 nm thickness has been studied using optical measurements. Result show that the thickness of the palladium cap layer affects the deloading of hydrogen from the hydrided films. The direct band gap of the SmH x films, calculated from the (αhν)2 vs hν plots, has been found to decrease with increasing thickness of the palladium overlayer, a fact attributed to the enhanced deloading of hydrogen. The removal of hydrogen from these films also leads to the formation of localized states, whose signature is clearly visible in these plots.

Effect of Palladium Overlayer on Samarium Hydride Thin Film Switchable Mirror: Electrochemical and Topographical Study

“…41) This is consistent with the reported observations that reversibility only occurs between a dihydride state and a trihydride state, and that one cannot remove hydrogen from the dihydride state. The effect of a Pd overlayer on the unloading of hydrogen from SmH 3À films has been optically determined for the same palladium overlayer thicknesses in one of our earlier studies, 42) which are in complete agreement with this study.…”