The kinetics of structural relaxation of bulk and ribbon glassy Pd40Cu30N10P20 monitored by resistance and density measurements

Density and in situ high precision electrical resistance measurements on bulk and ribbon glassy Pd40Cu30Ni10P20 in the initial state, after cold rolling and quenching from the supercooled liquid state are performed. Three relaxation stages resulting in different signs of the electrical resistance relaxation are determined. It is shown that the resistance change upon structural relaxation is predominantly controlled by the resistivity relaxation while the volume change has a minor effect on the resistance. Cold rolling has a complex impact on the electrical relaxation similar to the effect of plastic deformation on the dislocation anelasticity in crystals. Quenching of fully relaxed samples from the supercooled liquid state recovers structural relaxation and the amount of the resistance relaxation can be several times bigger than that in the initial state. It is concluded that relaxation of the electrical resistance as dependent on different conditions (bulk/ribbon samples, thermocycling, rolling and the parameters of quenching from the supercooled liquid state) is rather complex but it is unlikely that the degree of the relaxation is governed by the amount of the free volume. This conclusion agrees with the established fact of equal density of initial glassy and crystallized bulk samples and earlier findings of nearly equal shear viscosity of bulk and ribbon samples different by four orders of magnitude in the production quenching rate. (c) 2008 Elsevier B.V. All rights reserved.