Interaction of atomic hydrogen with evaporated lead films

Abstract

Atomic hydrogen has been shown, in contrast to molecular hydrogen, to interact with lead films to an extent corresponding to about five atoms per surface lead atom at 78 K. At 273 K incorporation is substantially faster and more extensive. There is some evidence for the formation at 273 K of a hydride of fixed composition (PbH_0·2) which is active in the adsorption of molecular hydrogen at 78 K. The kinetics of the formation and decomposition of this hydride have been investigated; gas-phase deactivation of thermally activated molecular species occurs at hydrogen pressures 10^–2 mmHg.