Facet formation, crystal growth

Fig. 5.4. Model of parallel-twin formation during crystal growth from Si melt. The growth interface is faceted as shown in (a), when a twin boundary is accidentally formed on a 111 facet face, another twin boundary is formed parallel to the first twin after lateral growth is promoted (from (b) to (d)). The direction of growth of the faceted dendrite should be parallel to the 111 facet plane in this model [16]...

Frequently, partial 3D models are applied, which consist typically of (crucible) melt and crystal. Such models are useful to perform basic studies on convection and crystallographic phenomena (facets, stress, strain, dislocations, ghde planes, etc.). In [28] it was shown that a small tilt of the ampoule relative to gravity can have a significant influence on the flow pattern and the flow velocities, fan and Tu [29] presented 3D simulations for the growth of YAG crystals, in which facet formation is coupled to heat flow and segregation. 

Shibata, M., Nitta, Y, Fujita, K., and Ichikawa, M. (2000). Facets formation of pyramidal Si nanocrystals selectively grown on Si(OOl) windows in ultrathin Si02 films, J. Crystal Growth 220, 449-456. 

It could also be shown that the system Li3BN2/c-BN interacts at elevated temperatures, leading to an obvious change in the morphology of the c-BN seed crystals. In all cases a formation of well faceted surfaces could be detected. From this system the growth of c-BN is most likely. 

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