Atomic hydrogen adsorption on sintered thin copper films

Atomic hydrogen adsorption on thin copper films deposited under UHV conditions was examined by means of Thermal Desorption Mass Spectrometry (TDMS) and measurements of corresponding relative resistance changes (ΔRR). It was found that at 78 K, within a coverage interval 0.02 < θ < 0.16, atomic hydrogen adsorption is characterized by a linear increase of ΔRR with increasing θ. TD spectra showed a large TD peak with a temperature maximum Tm at 300 K and traces of a very small TD peak (with θ on the order of 10−4) at a Tm of 170 K. At θ > 0.3 a weakly bound, inferred to be an induced form of the adsorbate was seen with a Tm at 230 K. No traces of molecular hydrogen adsorption could be observed until the H2 pressure, P, was below 0.1 Torr.