Intrinsic point defects and light interstitials in metals

Clusters consisting of a radioactive probe atom and various point defects in metallic hosts were studied by means of NMR-ON and PAC. NMR resonance signals were observed for (IV2)-I-131 clusters in Fe and (InV4)-In-114m clusters in Ni. Decoration of (InV2)-In-111 clusters by H atoms in W and Mo and by He atoms in W was monitored by PAC. The measurements yield the first reliable data on vacancy-hydrogen binding energies in these metals. The He-decoration results are in excellent agreement with the interpretation of He-desorption data and clearly show the existence of trap mutation.