Optical anisotropy in compositionally modulated Cu-Ni films by spectroscopic ellipsometry

Abstract
Spectroscopic ellipsometry studies (1.66–5.5 eV) of Cu-Ni thin films, containing short (0.62 and 4.13 nm) lattice-commensurate modulation wavelengths, have revealed a strong anisotropy of the dielectric function. These observations are discussed, in accordance with theoretical predictions for superlattices, in terms of the coherency strains. Other possible sources of anisotropy are also discussed in conjunction with other studies.