LOCAL MAGNETISM OF ULTRATHIN FCC-CO FILMS ON CU(100) BY IN-111 PROBES

Structural aspects and magnetic properties of ultrathin fee-Co films e pitaxially grown on Cu(100) have been investigated. Insight into the l ocal structure and magnetism has been gained through perturbed gamma g amma-angular correlation spectroscopy (PAC) using radioactive In-111 p robes. In 2-monolayer-thick Co films, a strongly reduced magnetic hype rfine field of B-hf = 5 T compared with the bulk value (B-hf(bulk) = 2 3.6 T) is observed, which is indicative for an outward shift of the In -111 from the substitutional surface site. Diffusion of Cu atoms from the Cu substrate an to the Co film occurs at elevated temperatures and leads to the formation of mixed Co-Cu environments at the In-111 prob es. (C) 1998 Elsevier Science B.V. All rights reserved.