Moessbauer reflectometry of ultrathin multilayer Zr(10 nm)/[Fe-57(1.6 nm)/Cr(1.7 nm)x26]/Cr(50 nm) film using synchrotron radiation

Time-resolved nuclear resonant reflectivity from ultrathin multilayer Zr(10 nm)/[Fe-57(1.6 nm)/Cr(1.7 nm)x26]/Cr(50 nm) film at grazing incidence angl es of synchrotron radiation has been investigated at the Nuclear Resonance Beamline of the European Synchrotron Radiation Facility. For interpretation of the results, complementary measurements of X-ray reflectivity and grazi ng incidence Moessbauer spectra of reflectivity and secondary electron yiel d are invoked. Peculiarities and depth-selectivity of the Moessbauer reflec tometry method in energy and rime domain are compared. It is shown that usi ng this method the information about top layers of the multilayer structure can be obtained. Computer fitting of the energy and time spectra shows the decreasing of the hyperfine magnetic field in the upper layers of investig ated multilayer structure. (C) 1999 Elsevier Science S.A. All rights reserv ed.