Chemical states and magnetic properties of (Co-Fe)-Al-O thin films

摘要

The chemical states of (Co-Fe)-Al-O magnetic thin films with various compositional ratios were investigated by X-ray photoelectron spectroscopy (XPS).Samples were prepared by using inductively coupled RF suttering.A non-reactive Ar atmosphere for both a Co-Fe alloy target and an Al_2O_3 ceramic target was used.Compositions of samples were varied to control the cathode power of the Co-Fe alloy target.Those with high (Co-Fe)/(Al-O) volume ratios exhibited excellent saturation magnetization (M_s) arising from the ideal chemical state of the non-oxidised CO-Fe alloy.Samples wit hlow (Co-Fe)/(Al-O) volume ratios high lighted a problem that the increase in volume of the Al-O layer could cause some degree of Fe oxidation in the Co-Fe alloy,which would lead to a decrease of M_s.