Surface mediated yttrium deuteride formation

Surface phenomena in the process of yttrium deuteride YDx (0.01<x<3) formation were studied simultaneously measuring work function and pressure changes, while D2 was interacting in situ with thin Y film deposited under UHV conditions. The transition metal–semiconductor accompanied by a drastic change of optical properties and resistance was observed. It was proved that at 298 K, at the beginning of the process, positively polarized deuterium adspecies are created. With increasing coverage, a negatively charged adsorbate is formed. The negatively charged adspecies slowly incorporate below the surface, and this leads to yttrium deuteride formation in the bulk. At 78 K the process of YDx formation is hindered due to the formation of a surface stable layer of deuterium adspecies.