Gold bits on a hot surface don't just melt away; they grow and shrink like a gambler's luck as they steal atoms from each other.
March 24, 2026
Original Paper
Substrate-Mediated Evaporation and Stochastic Evolution of Supported Au Nanoparticles
arXiv · 2603.20635
The Takeaway
We usually expect heat to cause a steady, predictable loss of mass. This study used high-tech microscopy to show that tiny gold particles actually trade atoms through a shared 'cloud,' causing individual particles to fluctuate in size and even grow larger while the overall group is supposedly evaporating.
From the abstract
We use in situ transmission electron microscopy with automated tracking to study supported gold nanoparticles (NPs) during high-temperature vacuum annealing. \rev{The average mass loss per NP is governed by a flat, nearly size-independent substrate-mediated evaporation profile.} On top of \rev{this mean shrinkage}, individual NPs show significant fluctuations in apparent growth or shrinkage, and NP volume follows a \rev{random-walk-like trajectory. To rationalize both the ensemble-mean behavior