Computer simulation of crystallization kinetics with non-Poisson distributed nuclei

TL;DR

This paper investigates how non-uniform distributions of nuclei affect crystallization kinetics in amorphous materials, showing deviations from classical models and proposing methods to distinguish different nucleation mechanisms experimentally.

Contribution

It introduces computer simulations of crystallization with non-Poisson distributed nuclei and compares results with classical JMA kinetics, highlighting the impact of different nucleation distributions.

Findings

Non-uniform nuclei distributions alter the Avrami exponent.

Simulated scattering curves can differentiate nucleation models.

Deviations from classical JMA kinetics are demonstrated.

Abstract

The influence of non-uniform distribution of nuclei on crystallization kinetics of amorphous materials is investigated. This case cannot be described by the well-known Johnson-Mehl-Avrami (JMA) equation, which is only valid under the assumption of a spatially homogeneous nucleation probability. The results of computer simulations of crystallization kinetics with nuclei distributed according to a cluster and a hardcore distribution are compared with JMA kinetics. The effects of the different distributions on the so-called Avrami exponent $n$ are shown. Furthermore, we calculate the small-angle scattering curves of the simulated structures which can be used to distinguish experimentally between the three nucleation models under consideration.