Negating Negative Heat Capacity in Nanoclusters

TL;DR

This paper demonstrates that negative heat capacity observed in nanoclusters is an artifact caused by out-of-equilibrium trapping, which affects all macroscopic quantities and challenges traditional thermodynamic assumptions.

Contribution

It reveals that negative heat capacity in nanoclusters results from out-of-equilibrium trapping, emphasizing the importance of initial conditions in thermodynamic analysis of small systems.

Findings

Negative heat capacity is an artifact of out-of-equilibrium trapping.

Trapping occurs in both canonical and microcanonical ensembles.

Macroscopic quantities depend on initial conditions in nanoclusters.

Abstract

It is shown that negative heat capacity in nanoclusters is an artifact of applying equilibrium thermodynamic formalism on a small system trapped out of equilibrium in a particular structural motif representing only part of the energetically available phase space volume. Trapping may occur in either the canonical or microcanonical ensemble, but it is unavoidable in the microcanonical. A more general consequence of trapping is that all macroscopic quantities determined for nanoclusters will depend on the initial conditions.