MANIFESTATION OF ANHARMONIC LOCALIZED VIBRATIONAL-MODES IN THE SPECIFIC-HEAT AND VIBRATIONAL-SPECTRUM OF FRESHLY PREPARED AMORPHOUS-ALLOYS

The low-temperature specific heat of freshly prepared and annealed amo rphous alloys Zr70Be30, Zr67Cu33, and Zr75Rh25 has been investigated e xperimentally. The integral parameters of the electronic and phonon sp ectra have been determined: the Sommerfeld coefficients and the Debye temperatures. Data from calorimetric and neutron experiments were comp ared on the basis of the theory of lattices with off-diagonal disorder and localized modes. It is concluded that a local rearrangement of th e structure occurs in freshly prepared samples as the temperature decr eases. A model of a bistable impurity configuration is proposed to exp lain this restructuring. (C) 1997 American Institute of Physics.