Synthesis and structure of ion‐beam sputtered multilayer Fe/Ni films

Multilayers of Fe/Ni with equal thickness of Fe and Ni layers have been deposited on Si and glass substrates using ion‐beam sputtering with composition modulation wavelength λ ranging from 20 to 160 A. X‐ray diffraction scans using Cu Kα radiation were made to look for the satellite peaks that are the signature of coherent multilayers. Satellite peaks were observed only when argon ion‐assisted deposition was used in preparing the multilayers. Read photographs using Fe Kα radiation show that the films are highly textured. All the diffraction rings in the Read photograph can be identified to a single face‐centered‐cubic (fcc) lattice for λ≤36 A. For higher wavelengths, rings corresponding to body‐centered‐cubic (bcc) Fe were observed in the Read photographs. Extended x‐ray absorption fine structure (EXAFS) measurements taken above the Fe K edge indicate that the Fe in the Fe/Ni multilayers are in fcc and bcc phases for wavelengths of 27.6 and 120 A, respectively. The average lattice parameter shows an enhan...