Kr-induced mixing and annealing effects at the Fe/SiO2 interface

Iron films e-beam evaporated onto high purity fused silica sheets were irradiated with krypton ions at the energy of 200 keV. After removal by chemical etching of the unmixed iron film, Rutherford backscattering spectrometry was used to measure the amount of mixed iron as a function of the irradiation dose. M\uf6ssbauer spectroscopy revealed states of different coordination for iron in the silica matrix. Mixed samples showed an optical reflectance in the visible region higher than that of pure silica. Effects of thermal annealings at 500 and 700\ub0C were also investigated. The influence of the chemical etching on the observed mixing effect has been excluded by a suitable test