CONVERSION ELECTRON MOSSBAUER-SPECTROSCOPY STUDY OF EPITAXIAL BETA-FESI2 GROWN BY MOLECULAR-BEAM EPITAXY

Epitaxial beta-FeSi2 grown by molecular beam epitaxy on Si(001) has be en studied by conversion electron Mossbauer spectroscopy with very goo d statistical accuracy and high resolution. This allowed investigation of the angular dependence of the line intensities revealing that the interpretation of the spectra in terms of a quadrupole coupling of two lines must be different from the one heretofore accepted. The electri c field gradients for the two Fe sites are antiparallel and in the bet a-FeSi2(001) direction. The isomer shifts are found in fair agreement with ab initio calculations.