ELASTIC ANOMALIES IN SINGLE-CRYSTAL COPPER NICKEL SUPERLATTICES GROWNBY MOLECULAR-BEAM EPITAXY/

Single crystal Cu/Ni superlattices with modulation wavelength from 8 t o 80 Angstrom were successfully grown by molecular beam epitaxy (MBE). The structure of the superlattice was characterized using two ways of X-ray diffraction geometry. Structural parameters, such as lattice di stortion, indistinct layers and fluctuation of the period, were extrac ted by model fitting to the X-ray diffraction spectra. Elastic propert ies were characterized by the Brillouin scattering measurement. Clear modulation wavelength dependence of the velocity Of Surface acoustic w ave was seen in (111) Cu/Ni superlattices. These results were quite di fferent from those previously reported.