title: Construction and stability of a close-packed structure observed in thin colloidal crystals.
abstract: We have characterized a close-packed structure of confined charged colloidal spheres, which has been recently discovered. Using different microscopy experiments, the vertically arranged hexagonal planes of n - hcp perpendicular are found to continuously evolve from the horizontally oriented stacks of n hexagonal planes (nDelta) following the maximum packing criterion, but discontinuously transform to a stack of n+1 square planes [(n+1)[SHAPE OF A SQUARE]]. Large mechanically stable domains with threefold twin structures are regularly observed in the suspended state at packing fractions between 0.4 and 0.58.
authors.affiliation: Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7, D-55128 Mainz, Germany.
authors.forename: Ana Barreira
authors.initials: AB
authors.lastname: Fontecha
authors.forename: Thomas
authors.initials: T
authors.lastname: Palberg
authors.forename: Hans Joachim
authors.initials: HJ
authors.lastname: Schöpe