Grain size effects on lateral islands in hard-sphere crystalsV. W. A. de Villeneuve, P. S. Miedema, J. M. Meijer and A. V. Petukhov
Van 't Hoff Laboratory for Physical and Colloid Chemistry, University of Utrecht - Padualaan 8, 3584 CH Utrecht, The Netherlands
received 10 April 2007; accepted in final form 5 July 2007; published September 2007
published online 31 July 2007
Due to the lateral stacking disorder, random hexagonally closed-packed hard-sphere crystals consist of lateral islands with different lateral positions A, B, and C, and as a consequence, different stacking. We investigate the extent of lateral stacking disorder as a function of grain size, and as a function of the fraction of FCC-stacked particles by laser scanning confocal microscopy and Monte Carlo simulations. We compare the simulations and microscopy data to relate stacking islands (2D domains with identical stacking type and direction) to lateral islands. Small crystals mainly contain single hexagonal planes, whereas larger crystals consist of a much larger number of lateral islands. Furthermore, the typical stacking island size is related to the FCC fraction. At high , more FCC islands nucleate, and these are more likely to combine into larger islands than the HCP islands.
61.72.Ff - Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, X-ray topography, etc.) .
82.70.Dd - Colloids .
87.64.Tt - Confocal microscopy .
© Europhysics Letters Association 2007