2019 Impact factor 2.176
Hadrons and Nuclei

Eur. Phys. J. A 13, 233-237 (2002)

Radioactive ions for solid-state investigations at magnetic surfaces and interfaces

H.H. Bertschat, K. Potzger, A. Weber and W.-D. Zeitz

Bereich Strukturforschung, Hahn-Meitner-Institut Berlin GmbH, D 14091 Berlin, Germany

(Received: 1 May 2001 / Revised version: 2 July 2001)

Hyperfine interactions observed at isomeric states of radioactive probe nuclei are used as a tool for solid-state investigations. This method is sensitive to atomic-scale properties. In recent years surface and interface investigations using radioactive probes delivered many results which can hardly be achieved by any other method. Several groups, e.g., from Konstanz, Leuven, Groningen, Aarhus, Uppsala, Tel Aviv, Pennsylvania, contributed to this field. Our group studies magnetic properties at surfaces and interfaces performing perturbed angular correlation (PAC) measurements in the UHV chamber ASPIC (Apparatus for Surface Physics and Interfaces at CERN). We take advantage of the enhanced variety of PAC probes delivered by the on-line mass separator ISOLDE. First, we report on measurements of magnetic hyperfine fields ( $B_{\rm hf}$) at Se adatoms on a ferromagnetic substrate using $\chem{^{77}Se}$ as a PAC probe. The investigation of induced magnetic interactions in nonmagnetic materials is a further subject of our studies. Here the nonmagnetic 4d element Pd is investigated, when it is in contact with ferromagnetic nickel. An outlook will be given on studies to be done in the future. The experiments were performed at the HMI, Berlin, and at CERN, Geneva.

75.70.-i - Magnetic properties of thin films, surfaces, and interfaces.
75.70.Rf - Surface magnetism.
76.80.+y - Mössbauer effect; other $\gamma$-ray spectroscopy.

© Società Italiana di Fisica, Springer-Verlag 2002