Year: 2026
Type: preprint
Abstract: Superionic conductors exhibit liquid-like ion transport within a rigid solid framework enabled by dynamical sublattice decoupling. In copper iodide (CuI), fast ion conduction emerges through structural transitions that reshape the local energy landscape, yet the microscopic evolution of diffusion topology across phase transitions remains insufficiently understood. By integrating machine-learning Molecular Dynamics (MLMD) with lattice dynamics, we elucidate the temperature-dependent ionic transport mechanism in CuI. The superionic transition in CuI manifests as a hierarchical evolution of transport dimensionality, progressing sequentially from localized vibrations to 1D channel transport, 2D in-plane diffusion, and ultimately isotropic 3D migration. This hierarchical evolution is driven by transverse acoustic phonon softening, which modulates migration barriers through direction-selective geometric confinement via a triangular-gate regulation mechanism.
Source: ChemRxiv
Authors: Wenjie Yang, Jialin Liu, Fawei Tang, Zhaochuan Fan
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7213937726