Jump to main content
Jump to site search

Issue 2, 2021
Previous Article Next Article

Phenomenology of the heating, melting and diffusion processes in Au nanoparticles

Author affiliations

Abstract

The paper reports the results of a molecular dynamics study of the heating and melting process of nanoparticles with 1985 to 84 703 atoms. Building on a previous study by the present authors [Bertoldi, et al., J. Phys. Chem. Solids, 2017, 111, 286–293] involving the energy versus temperature, the Lindemann index and the radial distribution function, the current work relies on the mean-square displacement, the Lindemann ratio and the simulated snapshots to characterize four regions in the process of heating-to-melting. A general pattern of the atomic configuration evolution upon heating and a systematics of the transition temperatures between the various identified steps, is proposed. In addition, the most significant, so-called “melting step” in this process is analyzed in terms of the quasi-chemical approach proposed by Bertoldi et al., which treats this step by invoking a dynamic equilibrium of the type Au (LEA-SPL) ⇌ Au (HEA-LPL) involving low-energy atoms (LEA) and high-energy atoms (HEA) forming the solid phase-like (SPL) and the liquid phase-like (LPL) states of the system, respectively. The “melting step” is characterized by evaluating the equal-Gibbs energy temperature, i.e., the “T0 temperature”, previously introduced by the current authors, which is the thermodynamic counterpart of the temperature of fusion of macroscopic elemental solids. The diffusion coefficients at T0 are determined, and their spatial and temperature dependence is discussed. In particular, the activation energy for the atom movements in the HEA-LPL/LEA-SPL mixture at T0 is reported. The consistency between the current phenomenological picture and microscopic interpretation of the thermodynamic, kinetic and atomic configuration information obtained is highlighted.

Graphical abstract: Phenomenology of the heating, melting and diffusion processes in Au nanoparticles

Back to tab navigation

Article information


Submitted
21 Aug 2020
Accepted
10 Dec 2020
First published
14 Dec 2020

Phys. Chem. Chem. Phys., 2021,23, 1298-1307
Article type
Paper

Phenomenology of the heating, melting and diffusion processes in Au nanoparticles

D. S. Bertoldi, E. N. Millán and A. Fernández Guillermet, Phys. Chem. Chem. Phys., 2021, 23, 1298 DOI: 10.1039/D0CP04442C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.


Social activity

Search articles by author

Spotlight

Advertisements