Aging, Fragility and Reversibility Window in Bulk Alloy Glasses

TL;DR

This study investigates the properties of bulk alloy glasses, revealing a specific compositional window where glasses are thermally reversible and do not age, indicating a self-organized state similar to proteins.

Contribution

It identifies a reversibility window in bulk alloy glasses where aging is suppressed, linking glass behavior to self-organization phenomena.

Findings

Reversibility window occurs at 0.09 < x < 0.145 in PxGexSe1-2x glasses.

Within this window, glasses are thermally reversing and do not age.

Outside the window, glasses exhibit aging behavior.

Abstract

Non-reversing relaxation enthalpies (DHnr) at glass transitions Tg(x) in the PxGexSe1-2x ternary display wide, sharp and deep global minima (~ 0) in the 0.09 < x < 0.145 range, within which Tgs become thermally reversing. In this reversibility window, glasses are found not to age, in contrast to aging observed for fragile glass compositions outside the window. Thermal reversibility and lack of aging seem to be paradigms of self-organization which molecular glasses share with protein structures which repetitively and reversibly change conformation near Tg and the folding temperature respectively.