ANELASTIC AND VISCOELASTIC BEHAVIOR OF AMORPHOUS ZR(65)CU(17.5)NI(10)A(17.5) IN THE RANGE OF THE GLASS-TRANSITION

Reversible (anelasticity) and the irreversible (viscosity) relaxations in the amorphous alloy Zr65Cu17.5Ni10Al7.5 have been investigated by means of creep and mechanic after-effect measurements of the shear str ain, which were performed in an inverted torsion pendulum. For the eva luation of the measurements a new relaxation model is proposed which t akes into account that in the range of the glass-transition temperatur e T-g the local atomic arrangement is steadely changing. By introducin g a finite mean life time tau(l) of local structure units we are able to trace the origin of the anelasticity and the viscosity to the same atomic relaxation processes. The temperature dependence of the viscosi ty eta measured between 560 K and 668 K shows a jump in the activation energy at T-g = 606 K from 2.1 eV below T-g to 5.6 eV above T-g.