Morphology transition during non-equilibrium growth: I. Study of equilibrium shapes and properties
School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel-Aviv University, Ramat-Aviv 69978, Israel Physica A: Statistical Mechanics and its Applications
(Impact Factor: 1.73).
02/1992; 181(1-2):136-155. DOI: 10.1016/0378-4371(92)90199-Z
We present a diffusion-transition scheme to study the penetration of a stable phase into a meta-stable one in systems described by a conserved order parameter. This approach is inspired by the specific example of solidification from supersaturated solution, for which we can take advantage of new experimental observations on surface kinetics. In this paper we present the approach and a study of solid-liquid equilibrium. The average shapes are compared with those evaluated by the Wulff construction. We calculate the fluctuations of the interface about the average shape as well as the temporal fluctuations in the diffusion field. Based on this, we propose a new strategy for experimental study of the kinetics of the phase transition. In part two we will present the morphologies observed in the simulations during non-equilibrium growth, focusing on the dense branching and dendritic morphologies, on their shape preserving envelope and on the transitions between them.
Available from: Yonathan Kozlovsky
- "To test the above idea, we included the additional assumed features in the Communicating Walkers model , changing it to a 'Communicating Spinors' model (as the particles in the new model have an orientation and move in quasi-1D random walk). The Communicating Walkers model  was inspired by the diffusion-transition scheme used to study solidification from supersaturated solutions   . The former is a hybridization of the " continuous " and " atomistic " approaches used in the study of non-living systems. "
[Show abstract] [Hide abstract]
ABSTRACT: In nature, microorganisms must often cope with hostile environmental conditions. To do so they have developed sophisticated cooperative behavior and intricate communication capabilities, such as: direct cellcell physical interactions via extra-membrane polymers, collective production of extracellular "wetting" fluid for movement on hard surfaces, long range chemical signaling such as quorum sensing and chemotactic (bias of movement according to gradient of chemical agent) signaling, collective activation and deactivation of genes and even exchange of genetic material. Utilizing these capabilities, the colonies develop complex spatio-temporal patterns in response to adverse growth conditions. We present a wealth of branching and chiral patterns formed during colonial development of lubricating bacteria (bacteria which produce a wetting layer of fluid for their movement). Invoking ideas from pattern formation in non-living systems and using "generic" modeling we are able to reveal nov...
Physica A: Statistical Mechanics and its Applications 08/1992; 187(1):87-111. · 1.73 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: In a preceding paper we have presented a new diffusion-transition approach to study pattern formation in systems described by a conserved order parameter on a square lattice. Here we describe and analyze two of the different morphologies observed during growth far from equilibrium: the dense branching morphology (DBM) and the dendritic morphology. Both have been found to represent clearly distinct morphological "phases". They can be characterized by their envelope: convex for DBM and concave for dendritic morphology. They both propagate at constant velocity. The velocity scales with different powers of the chemical potential for the two different morphologies. For the DBM, the branch width is proportional to the diffusion length. The transitions between the morphologies and their growth behavior are studied as a function of the chemical potential and the macroscopic driving force (supersaturation).
Physica A: Statistical Mechanics and its Applications 08/1992; 187(1):87-111. DOI:10.1016/0378-4371(92)90411-I · 1.73 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.