Massive Fluctuations in the Derivatives of Pair Distribution Function Minima and Maxima During the Glass Transition

Abstract

Parametric changes in the first coordination shell (FCS) of a vitreous metallic Pd42.5Cu30Ni7.5P20 alloy are analysed, aiming to confirm the identification of the glass transition temperature (Tg) via processing of XRD patterns utilising radial and pair distribution functions (RDFs and PDFs) and their evolution with temperature. The Wendt–Abraham empirical criterion of glass transition and its modifications are confirmed in line with previous works, which utilised the kink of the temperature dependences of the minima and maxima of both the PDF and the maxima of the structure factor S(q). Massive fluctuations are, however, identified near the Tg of the derivatives of the minima and maxima of the PDF and maxima of S(q), which adds value to understanding the glass transition in the system as a true second-order-like phase transformation in the non-equilibrium system of atoms.

Keywords

• metallic glasses
• glass transition
• fluctuations
• second-order phase transition