Synchrotron X-Ray Study on Structures of Ni₈₀Fe₂₀/Cu Superlattices

We showed that, in contrast to the results in literature, the Bragg peak intensity of Ni₈₀Fe₂₀/Cu superlattices is enhanced at the incident x-ray energy slightly higher than the absorption edge of the heavier element (Cu). The atomic density at Ni₈₀Fe₂₀/Cu interface was analysed by the diffraction anomalous fine structure technology with the incident angle of x-ray fixed at the first Bragg peak. Our results demonstrate the epitaxy growth of Ni₈₀Fe₂₀/Cu superlattices. Upon annealing, the epitaxity of Ni₈₀Fe₂₀/Cu multilayers becomes poor but the local crystallinity in each layer is improved.