Universality in the non-Newtonian viscous flow behavior of AsxSe1 − x liquids: Results from capillary rheometry

The shear rate dependence of the viscosity of AsxSe1 − x (5 ≤ x ≤ 40) liquids is studied using capillary rheometry. All liquids display non-Newtonian rheological behavior in the form of shear thinning. The onset of such behavior is characterized by shear rates that are nearly four orders of magnitude slower than the average rate of structural relaxation. Proper normalization of the viscosity vs. shear rate data demonstrates a remarkable universality in this behavior, irrespective of chemical composition, structure, topology and temperature. The existence of such universality suggests an underlying commonality in the fundamental atomistic mechanism of shear thinning in these chalcogenide liquids.