Sound attenuation in the superconducting amorphous alloy ZrTiCuNiBe

The superconducting energy gap and the parameter of the intensity of electron scattering at two-level systems in amorphous ZrTiCuNiBe are determined from the results of measurements of sound attenuation. The mechanism of adiabatic renormalization of the amplitude of coherent tunneling is used for a quantitative description of the peculiarities of sound absorption in the vicinity of critical temperature.Comment: 4 pages, LaTeX, 2 Postscript figures corrected, submitted to Low Temp. Phy

Elastic constants of borocarbides. New approach to acoustic Measurement technique

A new version of the phase method of determining the sound velocity is proposed and implemented. It utilizes the ``Nonius'' measurement technique and can give acceptable accuracy (~1%) in samples of submillimeter size. Measurements of the sound velocity are made in single-crystal samples of the borocarbides RNi2B2C (R = Y,Lu,Ho). The elastic constants and the Debye temperature are calculated.Comment: 5 figures, 2 table