Interface magnetism using radioactive atoms

With the use of radioactive probe atoms it is possible to trace - with monolayer resolution - magnetic properties through a multilayer system by the measurement of magnetic hyperfine interactions. In a first series of experiments we investigated the Ni/Pd interface, starting with the surfaces of Ni and Pd single crystals using the chalcogen probe (77)Se as an isolated adatom. The magnetic hyperfine fields on Ni surfaces were found to deviate considerably from the bulk value. Furthermore we investigated the induced magnetization in Pd using the 4d-transition element (100)Pd and the sp-element (111)Cd as radioactive probes. When ultrathin Pd was in contact with Ni, stable magnetic hyperfine fields were detected indicating the Formation of stable magnetic moments in Pd. In thick Pd (single crystal) magnetic moments were induced up to at least 7 atomic layers away from the interface and these moments were fluctuating. (C) 1999 Elsevier Science B.V. All rights reserved.