Solid-state amorphization of As45S55 alloy induced by high-energy mechanical milling

Abstract

Complete solid-state amorphization from parent crystalline-amorphous As45S55 alloy was first detected under high-energy milling in a dry mode. The amorphized alloy exhibits stretched X-ray diffraction halos proper for glassy substances with well-expressed first sharp diffraction peak near reciprocal space scattering vector of 1.16Å−1, which corresponds to 5.42Å in a real-space interplanar distance and 22.11Å in a correlation length. These peak parameters are in good respect with compositional extrapolation for melt-quenched As-rich compositions in As-S system. At the basis of comparison between first sharp diffraction peak and most intensive interlayer reflexes in overstoichiometric molecular As-S polymorphs, the network of amorphized As45S55 is assumed as random packing of multifold cycle-type entities proper to these polymorphs, where the role of realgar As4S4 cage formations is notably most important. Double-Tg relaxation effect identified by multifrequency temperature modulated differential scanning calorimetry is shown to be character for As45S55 alloy amorphized under high-energy milling.