Dynamics and thermodynamics of decay in charged clusters

Abstract

We propose a method for quantifying charge-driven instabilities in clusters, based on equilibrium simulations under confinement at constant external pressure. This approach makes no assumptions about the mode of decay and allows different clusters to be compared on an equal footing. A comprehensive survey of stability in model clusters of 309 Lennard-Jones particles augmented with Coulomb interactions is presented. We proceed to examine dynamic signatures of instability, finding that rate constants for ejection of charged particles increase smoothly as a function of total charge with no sudden changes. For clusters where many particles carry charge, ejection of individual charges competes with a fission process that leads to more symmetric division of the cluster into large fragments. The rate constants for fission depend much more sensitively on total charge than those for ejection of individual particles.Comment: 10 pages, 6 figures, Special Issue of Molecular Physics for the 70th birthday of Jean-Pierre Hanse

Dipolar-coupled moment correlations in clusters of magnetic nanoparticles

“…For the Monte Carlo simulations, we used a constant pressure approach to generate an ensemble of 320 clusters with each cluster containing 32 individual cores [89]. Each core was modeled as a point dipole with a spherical exclusion volume that was proportional to the magnetic moment and had an anisotropy energy density of 13 kJ/m 3 .…”

Where Do the Ions Reside in a Highly Charged Droplet?

“…More often than not, these droplets comprise several ions instead of a single ion. Thus far, there have been many studies on the location of a single ion in clusters with a diameter up to a few nanometers. − Differently, the study of the structure of charged clusters with multiple ions has been initiated but it is still incomplete. − In this article we investigate (a) the spatial distribution of ions in multiply charged liquid mesoscopic clusters and the structure of the solvent and (b) the electric field on the mesoscopic cluster surface. The mesoscopic clusters are often called nanodrops, and hereafter we shall refer to them as such.…”

Where Do the Ions Reside in a Highly Charged Droplet?

“…[1][2][3][4][5][6][7][8][9][10][11][12] Differently, the study of the structure of charged clusters with multiple ions has been initiated but it is still incomplete. [13][14][15][16][17][18][19][20][21][22] In this article we investigate the spatial distribution of ions in multiply charged mesoscopic clusters and the structure that the ions induce in the solvent. The mesoscopic clusters are often called nano-drops.…”