Slanted stacking faults and persistent face centered cubic crystal growth in sedimentary colloidal hard sphere crystals†

Hard sphere crystal growth is a delicate interplay between kinetics and thermodynamics, where the former is commonly thought to favour a random hexagonal close packed structure and the latter leads to a face centered cubic crystal. In this article, we discuss the influence of slanted stacking faults on the growth of sedimentary colloidal crystals from dispersions with high initial volume fraction and particles that sediment relatively fast. We find that the presence of these persisting faults locally induces fcc structure, while defect free regions form rhcp crystals as expected for a system where kinetics dominate. These results are promising for use in epitaxial growth of colloidal crystals, where proper templating could lead to almost perfect fcc crystals with selectively incorporated defects.