Understanding the Fundamentals of Crystal Growth

Abstract

The fundamentals of crystal growth are explored using a combination of experimental and computational methods developing new methods of analysis and observing never seen before crystal growth phenomena. Firstly, using CrystalGrower, the morphology and crystallographic growth axes of any crystal system can be mapped to define the energy space of the crystals building units. This was achieved by building a tool called CrystalAspects that measures the 3D properties of all crystals output from CrystalGrower in terms of aspect ratios, surface area, volume and crystallographic directions and comparing this to the free energy of crystallisation, ∆GCryst, of each building unit. This output provides a direct tool to understand the relationship between building unit and morphology and furthermore tailor crystallisation to yield desired crystals. This was then built on, by investigating experimentally grown crystals and comparing this to the simulated crystals to understand the resultant morphology and topology and ∆"!"#$% of the building units. These comparisons then escalated by predicting growth and dissolution rates and furthermore inputting growth modifiers to understand how growth modifiers interact with the crystal during growth. Experimentally, High-Speed Atomic Force Microscopy (HS-AFM) revealed the complexities and intricacies of crystal growth with supporting videos clearly outlying the observations. This revealed phenomena never observed before such as, dynamic growth where the surface was observed to be both growing and dissolving simultaneously, meta-stable faceted ledges at low supersaturation, formation of macroledges under extreme conditions, the effect of hollow screw cores on crystal growth and the formation of clusters on the surface of the crystal, whilst showing the development of hollow pockets within crystals. HS-AFM is an extremely powerful technique that bridges the gap to observe the dynamic processes of crystal growth. All videos of the observed phenomena with links to each chapter can be found at https://drive.google.com/drive/folders/1tX9YfVr7Tu7bfdZujBw1lY2sE38vkfLr?usp=shar e_link. Please download all the videos and watch the observed phenomena as you read the thesis.

Date of Award	28 Jul 2023
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Michael Anderson (Main Supervisor) & Roger Davey (Co Supervisor)