Crystal growth structure

Figure 16.6 Crystal structures of a4T, a 6T and a 8T. Adapted from T.Siegrist, C. Kloc, R. A. Laudise, H. E. Katz, R. C. Haddon, Crystal Growth Structure and Electronic Band Structure ofalpha-4T Polymorphs Adv. Mater. 10, 5, 379-382. Copyright WHey-VCH Verlag GmbEI Co. KCaA. Reproduced with permission...

Tanigaki K, Kuroshima S and Ebbesen T W 1995 Crystal growth and structure of fullerene thin films Thin Soiid Fiims 257 154-65... 

Polymer crystals form by the chain folding back and forth on itself, with crystal growth occurring by the deposition of successive layers of these folded chains at the crystal edge. The resulting crystal, therefore, takes on a platelike structure, the thickness of which corresponds to the distance between folds. 

The theory of crystal growth accordingly starts usually with the assumption that the atoms in the gaseous, diluted, or hquid mother phase will have a tendency to arrange themselves in a regular lattice structure. We ignore here for the moment the formation of poly crystalhne solids. In principle we should start with the quantum-mechanical basis of the formation of such lattice structures. Unfortunately, however, even with the computational effort of present computers with a performance of about 100 megaflops... 

Here r is the distance between the centers of two atoms in dimensionless units r = R/a, where R is the actual distance and a defines the effective range of the potential. Uq sets the energy scale of the pair-interaction. A number of crystal growth processes have been investigated by this type of potential, for example [28-31]. An alternative way of calculating solid-liquid interface structures on an atomic level is via classical density-functional methods [32,33]. 

A normal diffusion process, however, runs at a finite concentration of particles different from zero. In this situation it was found [101] that a fractal character (73) of the resulting structure is restricted to an interval a < R < if), where d is the diffusion length (67). Larger clusters have a constant density on a length scale larger than They are no longer fractal there. These observations have various consequences for crystal growth, and will be discussed in the next section. 

J. Holuigue, O. Bertrand, E. Arquis. Solutal convection in crystal growth effect of interface curvature on flow structuration in a three-dimensional cylindrical configuration. J Cryst Growth 180 591, 1997. 

Crystal growth 6.7.4,3 Crystal structure and lattice parameters 6.7.2.4.1 Electrical and magnetic properties 6.7.2.4.1... 

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