Interaction potentials and their effect on crystal nucleation and symmetry

Journal Article · Sat Dec 15 00:00:00 EST 1979 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.438311· OSTI ID:5865597

Hsu, C S; Rahman, A

Molecular dynamics technique has been used to study the effect of the interaction potential on crystal nucleation and the symmetry of the nucleated phase. Four systems, namely rubidium, Lennard-Jones, rubidium-truncated, and Lennard-Jones-truncated, have been studied each at reduced density 0.95. Two types of calculations were performed. Firstly, starting from a liquid state, each system was quenched rapidly to a reduced temperature of approx.0.1. The nucleation process for these systems was monitored by studying the time dependence of temperature and the pair correlation function, and the resulting crystalline structure analyzed using among other properties the Voronoi polyhedra. Only in the case of rubidium was a b.c.c. structure nucleated. In the other three cases we obtained a f.c.c. ordering. Secondly, we have studied the effect of changing the interaction potential in a system which has already achieved an ordered state under the action of some other potential. After establishing a b.c.c. structure in a rubidium system, the change in the symmetry of the system was studied when the pair potential was modified to one of the other three forms. The results from both types of calculations are consistent: the rubidium potential leads to a b.c.c. structure while the other three potentials give an f.c.c. structure. Metastable disordered structures were not obtained in any of the calculations. However, the time elapse between the moment when the system is quick-quenched and the moment when nucleation occurs appears to depend upon the potential of interaction.

• Research Organization: Argonne National Laboratory, Argonne, Illinois 60439
• OSTI ID: 5865597
• Journal Information: J. Chem. Phys.; (United States), Vol. 71:12
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
NUCLEATION
INTERATOMIC FORCES
RUBIDIUM
CORRELATIONS
CRYSTALS
LENNARD-JONES POTENTIAL
SYMMETRY
ALKALI METALS
ELEMENTS
METALS
640300* - Atomic
Molecular & Chemical Physics
360104 - Metals & Alloys- Physical Properties
656000 - Condensed Matter Physics