Journal of Alloys and Compounds 286 (1999) 322-332

Moessbauer reflectometry of ultrathin multilayer Zr(10 nm)/[57Fe(1.6 
nm)/Cr(1.7 nm)x16]/Cr(50 nm) filmu using synchrotron radiation

M.A. Andreeva, S.M. Irkaev, V.G. Semenov, K.A. Prokhorov, N.N. 
Salaschenko, A.I. Chumakov, R. Ruffer

Tmire-resolved nuclear resonant reflectivity from ultrathin multilayer 
Zr(10nm)/[57Fe(1.6nm)/Cr(1.7nm)x26]/Cr(50nm) film at grazing incidence 
angles 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 grazing incidence Moessbauer spectra of reflectivity and 
secondary electron yield are invoked. Peculiarities and depth-selectivity 
of the Moessbauer reflectometry method in energy and time domain are 
compared. It is shown that using 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 investigated multilayer structure.