Decrease in electrical resistivity on depletion of islands of mobility during aging of a bulk metal glass.

The effect of structural relaxation on electrical resistivity, ρ, of strain-free ZrTiCuNiBe bulk metallic glass was studied during isothermal aging at several temperatures, Ts. Since cooling of a liquid metal increases its resistivity ρ, one expects ρ to increase on aging toward ρ at T = T. Instead, ρ decreased non-exponentially with the aging time.

Intrinsic correlation between β-relaxation and spatial heterogeneity in a metallic glass.

β-relaxation has long been attributed to localized motion of constituent molecules or atoms confined to isolated regions in glasses. However, direct experimental evidence to support this spatially heterogeneous scenario is still missing. Here we report the evolution of nanoscale structural heterogeneity in a metallic glass during β-relaxation by utilizing amplitude-modulation dynamic atomic force microscopy.

Fictive temperature, structural relaxation, and reality of residual entropy.

By determining the fictive temperature, Tf, in two ways from the same Cp data, we investigate whether the residual entropy, Sres, of a glass could be an artifact of using the Cp d ln(T) integral in the glass-liquid temperature range. Although the integral gives only the upper and lower limits of the real entropy change, it is still useful and is distinguished as Delta(sigma). We determine Tf(sigma) from Delta(sigma) and the usual TfH from the Cp dT integral for two metal alloy glasses, a basalt composition glass and a spray-quenched propylene glycol glass from the available data, and find that Tf9sigma is about the same as TfH within errors.