New insights into CoFe/n-Si interfacial structure as probed by X-ray photoelectron spectroscopy

X-ray photoelectron spectroscopy (XPS) is a well known tool in studying the physical and chemical properties of surface/interfaces which provides the element specific, non-destructive and quantitative information. In the present study, information about the surface chemical states of interfacial structure of CoFe thin films on n-Si substrates has been studied from XPS technique. The surface of the samples has also been cleaned from ion beam etching for 30 min with Ar+ ions to record the XPS spectra. The observation shows that the Si atoms are present within the probed surface layer due to interfacial intermixing across the interface which is due to strong chemical reactivity of n-Si substrate. A shift in the binding energy peaks of Fe2p and Co2p has also been observed which could be due to the formation of silicide phases as a result of interfacial intermixing. XPS results have indicated the formation of silicide phases across the interfaces which poses interfacial antiferromagnetic coupling across CoFe/n-Si interface to affect the magnetic behaviour. It has been found that the present XPS results are in well support with our earlier study. (C) 2016 The Authors. Publishing services by Elsevier B.V. on behalf of Vietnam National University, Hanoi.