OBSERVATION OF MAGNETISM OF FE AT AN INTERSTITIAL SITE IN A METAL HOST

Using perturbed angular (gamma-ray) distribution techniques and in-bea m Mossbauer spectroscopy, we have investigated the interstitial and su bstitutional site occupation and the site-specific magnetic behavior o f implanted Fe impurities in fee Yb. As a new feature, strong magnetis m is observed for interstitial Fe atoms, which exhibit a rather stable local moment and Korringa-like spin dynamics. The essential experimen tal results are found to be consistent with the predictions of local s pin density calculations, carried out for relaxed octahedral interstit ial and for substitutional Fe sites in Yb. These combined results yiel d insight into basic features of magnetic moment formation and local s tructure at an interstitial site.