From Continuous to First-Order-Like: Amorphous-to-Amorphous Transition in Phase-Change Materials
Abstract
Polymorphism is ubiquitous in crystalline solids. Amorphous solids, such as glassy water and silicon, may undergo amorphous-to-amorphous transitions (AATs). The nature of AATs remains ambiguous, due to diverse system-dependent behaviors and experimental challenges to characterize disordered structures. Here, we identify two ordered motifs in amorphous phase-change materials and monitor their interplay upon pressure-induced AATs. Tuning temperature, we find a crossover from continuous to first-order-like AATs. The crossover emerges at a special pressure-temperature combination, where the AAT encounters a maximum in crystallization rate. Analyzing the two ordered motifs in a two-state model, we draw a phenomenological parallel to the phase transition behavior of supercooled water near its second critical point. This analogy raises an intriguing question regarding the existence of a critical-like point within amorphous solids.
Cite
@article{arxiv.2504.07154,
title = {From Continuous to First-Order-Like: Amorphous-to-Amorphous Transition in Phase-Change Materials},
author = {Tomoki Fujita and Yoshio Kono and Yuhan Chen and Jens Moesgaard and Seiya Takahashi and Arune Makareviciute and Sho Kakizawa and Davide Campi and Marco Bernasconi and Koji Ohara and Ichiro Inoue and Yujiro Hayashi and Makina Yabashi and Eiji Nishibori and Riccardo Mazzarello and Shuai Wei},
journal= {arXiv preprint arXiv:2504.07154},
year = {2025}
}