Growth sectors, diamond

When nickel or cobalt is used as the solvent/catalyst, these elements are incorporated in the diamond lattice as optically active point-defects, but only in 111 growth sectors [77, 78],... 

Figure 6 Diamond crystal growth, showing (clockwise) growth sectors as indicated by the dashed lines, stress in the X-Y plane, stress in the X-Z plane, and overall crystalline quality in the X Z plane [24], (Reproduced from Diamond and Related Materials, 8, Mossbrucker, J. et al., 3-D determination of the location and absolute amount of sp and sp bound carbon and stress components in CVD diamond films using multi-color polarized Raman spectroscopy, pp. 663-667. Copyright 1999, with permission from Elsevier Science.)...

IV. NEARLY PERFECT CRYSTALS OF DIAMOND A. Growth Sectors... 

Transmission electron microscopy, electron diffraction, and Raman spectroscopy indicated that the (001) growth sector has less defects, whereas the (111) sector shows many stacking faults and twins. Epitaxy on the ((X)l) surface of diamond was the first choice in searching for electronic quality films. 

Figure 5 Growth sectors of a diamond crystal. Normalized growth rates v are indicated.

Graphite codeposition was the main concern at the beginning of the CVD method because of an insufficient concentration of H° in deposition reactors. The sp component is of negligible importance for crystals grown in an H°-rich environment when compared with stacking faults and twinning. These planar defects disturb the diamond lattice predominantly in the < 111 > growth sectors (41—43). 

Neutral vacancies formed during the growth are rarely observed in CVD crystals. Instead, vacancies appear as silicon (or silicon pair)-vacancy complexes. This defect is frequently observed in diamond crystals grown on Si. Growth sector (111) can be doped with Si to levels above 1 at%. This doping level introduces displacement disorder of atoms in the diamond lattice to such an extent that the 1332 cm Raman peak almost disappears. This means that the vibration mode related to the optical phonon becomes weak in such a distorted lattice. 

The four horizontal lines in Fig. 9 indicate the relative concentrations of isolated substitutional nitrogen in the major growth sectors of a standard nitrogen-containing synthetic diamond. 

Thus, the known sectorial character of the HTHP diamond crystals [ 27 ] well manifests itself in the electrochemical measurements. On the whole, the difference in the electrochemical behavior of the individual faces can he primarily ascribed to different boron concentration in their adjacent growth sectors, resulting from the different ability of the diamond crystal faces to incorporate the boron dopant during the growth process, rather than to different surface atomic densities or other purely surface properties. 

Fig. 2.2. A diamond-shaped crystal showing four sectors and the folds lying parallel to the (110) growth faces...

Bulanova G. P., Pearson D. G., Hauri E. H., and Griffin William L. (2002) Carbon and nitrogen isotope systematics within a sector-growth diamond from the Mir kimberlite, Yakutia. Chem. Geol. 188, 105-123. 

The crystallographic (110) fold, which was first proposed by Bassett, Frank and Keller (1963), is essentially a path in the diamond lattice. Hence, the hollow pyramid itself is indicative of the dominance of regular chain folding in single crystals. Bassett showed that the fold surfaces in the no sectors were parallel to 312 planes and that the fold surfaces in the lOO sectors were parallel to 20l planes. A match between 312 and 20l is obtained only for a certain fixed ratio of H0 and lOO growth. A preference for such a growth ratio was indicated... 

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