PURE NUCLEAR REFLECTION FROM ~(natural)FeN_(0.7)/~(57)FeN_(0.7)ISOTOPIC MULTILAYER

摘要

Isotopic multilayer of ~(natural)FeN_(0.7) /~(57)FeN_(0.7) has been prepared using reactive ion beam sputtering. SIMS measurements show that self-diffusion of Fe in the film is low and is typical of amorphous materials. The periodic multilayer of composition: Float Glass (substrate)/~(nat)FeN(30A)/[57FeN(20A)/~(nat)FeN(30A)]_(x10) was used for measurement of nuclear resonance reflectivity at the NRS beamline of SPring-8 synchrotron radiation source. Nuclear resonance reflectivity, which is delayed in time, was separated from prompt electronic reflectivity using time filtering. A pure nuclear Bragg peak because of isotopic periodicity was observed at an angle of 0.55 deg. (for 14.4 KeV radiation) where electronic scattering was of the order of 10~(-3). Use of nuclear resonance reflectivity in the measurements of self-diffusion of Fe in the compound is discussed.