2024/02/26 by Gadha Ramesh, Ramesh, Gadha, Ved Mahajan +5 · 2 citations
Earth and Planetary Sciences · Materials Science · #Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Liquid Crystal Research Advancements #Material Dynamics and Properties #Materials Science (cond-mat.mtrl-sci) #Statistical Mechanics (cond-mat.stat-mech) #nanoparticles nucleation surface interactions
paper · pdf · doi:10.48550/arxiv.2402.16761
openalex publication_date 2024/02/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Much attention has been devoted to understanding the microscopic pathways of phase transition between two equilibrium condensed phases (such as liquids and solids). However, the microscopic pathways between non-equilibrium, non-diffusive amorphous (glassy) phases still remain poorly understood. In this work, we have employed computer simulations, persistence homology (a tool rooted in topological data analysis), and machine learning to probe the microscopic pathway of pressure-induced non-equilibrium transition between the low- and high-density amorphous (LDA and HDA, respectively) ice phases of TIP4P/2005 and ST2 water models. Using persistence homology and machine learning, we introduced a new order parameter that unambiguously identifies the LDA and HDA-like local environments. The system transitions continuously and collectively in the order parameter space via a pre-ordered intermediate phase during the compression of the LDA phase. The local order parameter susceptibilities show a maximum near the transition pressure (P^*) -- suggesting maximum structural heterogeneities near P^*. The HDA-like clusters are structurally ramified and spatially delocalized inside the LDA phase near the transition pressure. We have further investigated the (geometrical) structures and topologies of the LDA and HDA ices formed via different protocols and also studied the dependence of the microscopic pathway of phase transition in the order parameter space on the protocol followed to prepare the initial LDA phase. Finally, the method adopted here to study the microscopic pathways of transition is not restricted to the system under consideration and provides a robust way of probing phase transition pathways involving any two condensed phases at both equilibrium and out-of-equilibrium conditions.