Abstract
We provide rare experimental evidence of ergodicity at the atomic level using high-resolution transmission electron microscopy. By examining the phase transition from η-alumina to θ-alumina in bayerite Al(OH)3 crystallites, we directly observe and quantify the ergodic nature of this transformation. The study demonstrates that at the nanoscale, the time a particle spends in various states during a phase transition aligns with the overall system's state distribution, thus confirming ergodic theory predictions. This research challenges traditional deterministic models of phase transitions in macroscopic crystals, suggesting a broader applicability of ergodic principles in understanding the dynamics of structural phase changes.