Kinetic Monte Carlo simulations of the morphological evolution of orthorhombic precipitates from solution

In this paper, a kinetic Monte Carlo (k-MC) simulation was applied to the growth of crystals with a base-centered orthorhombic crystal structure with the intention of capturing the effect of material and environmental parameters such as nucleation rate, temperature, lattice energy, diffusion hop barrier, Ehrlich-Schwoebel barrier and nucleation rate. A seeded random nucleation model was utilized for the simulation and events allowed included solidification from liquid state, attaching/adsorbing to existing particles, diffusing on the surface or into vacancies in the existing crystal (first or second neighbor) and detaching from an existing crystal. Different energy functions for lattice sites with respect to coordination numbers, including linear, logarithmic, power law, exponential and constant energy functions, were implemented and compared. Five different structures were identified: Rectangular prisms, angular shaped particles, thin, sheet-like structures or platelets, a particle network and random distribution. It was found that low or nonexistent barriers resulted in rectangular prism shapes. When lattice energies were implemented, particle shapes became more angular.