An ENDOR study of H atoms in HD solid at 4.2 K

An ENDOR spectrum of H atoms in the γ-ray irradiated HD solid was measured at 4.2 K for elucidating the local environment of HD molecules surrounding H atoms. The analysis of the ENDOR spectrum indicates that the H atoms are not trapped in substitutional but in pseudo octahedral interstitial sites of HD solid. It is postulated that an H atom, produced by the γ-irradiation, initially enters the octahedral interstitial site, and then the HD molecules at the first nearest site from the H atom are pushed back by zero-point vibration of the H atom.