Characterization of Fe-Nb sputtered thin films

Structure, composition and chemical behavior of co-sputtered Fe-Nb thin films are analyzed by different techniques, as conversion electron Mössbauer spectroscopy, x-ray photoelectron spectroscopy and x-ray diffraction. It is shown that oxygen is determinative in hindering the Fe-Nb alloy formation and, as a result, Fe1−xO and Nb2O5 occur in significant amounts, even in vacuum. In spite of the oxygen role, a Fe-Nb alloy is formed in little amounts, which increase as the Nb content is increased. The increase of the Nb content is also related with the increase of Fe1−xO and with a decreasing of the metallic Fe present. Mössbauer data indicate the Fe-Nb phase present is the Fe2Nb Laves phase.