Abstract
We explore the crystallization in a colloidal monolayer on a structured template starting from a few-particle nucleus. The competition between the substrate structure and that of the growing crystal induces a new crystal growth scenario. Unlike with the crystal growth in the bulk where a well-defined and connected crystal–fluid interface grows into the fluid, we identify a mechanism where a ‘compatibility wave’ of the prescribed nucleus with the underlying substrate structure dictates the growth direction and efficiency. The growth process is strongly anisotropic and proceeds via transient island formation in front of an initial solid–fluid interface. We demonstrate the validity of this compatibility wave concept for a large class of substrate structures including a square lattice and a quasicrystalline pattern. Dynamical density functional theory that provides a microscopic approach to the crystallization process is employed for colloidal hard spheres. Our predictions can be verified in experiments on confined colloids and also bear consequences for molecular crystal growth on structured substrates.
Highlights
We explore the crystallization in a colloidal monolayer on a structured template starting from a few-particle nucleus
The compatibility wave concept is valid for a large variety of substrate structures, e.g. for a square lattice and a quasicrystalline pattern
As the growth process is similar in all presented cases, it can be extracted that for other kinds of substrate potentials, a crystal will grow in analogy to our prediction by a compatibility wave, which drives the growth preferable at compatibility positions
Summary
To reveal the underlying mechanism, we focus on a much simpler setup of planar growth and we examine a nucleus consisting of a stripe of particles and analyse the growth perpendicular to the long side of the stripe. In figures 2(a) and (c) the patterns of crystal sites and the minima positions of the substrate potential are shown for two different values of φ. The regions of short critical times t∗ match well with the proposed positions from figure 3(a) This can be understood as here the positions of the substrate potential coincide well with the crystal lattice sites. Close to the compatibility positions, the slope of the curves in the space–time plot is still much smaller than that at less compatible positions This mechanism can be examined in an effective one-dimensional channel, where the external potential is simplified to a cosine-wave parallel to the growth direction, with lattice constant aV and amplitude V0.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
