Crystallographic indices

Figure 2.22 Models of packing of chains in form I of sPP according to space groups (a) Ibca59 and (b) P2 /a.146 Arrows indicate crystallographic twofold axes, present in (a) and lost in (b). In (b) chains are rotated by nearly 5° around chain axes, according to direction indicated by the arrows.

Figure 2.24 Models of packing of chains in a-form of sPS according to space groups (a) / 3cl52 and (b) P3150. In (a) dotted lines indicate crystallographic glide planes coincident with local glide planes of chains. In (b) triplets of chains are rotated around threefold axes and crystallographic glide planes are lost.

Figure 9.18 Idealized structures of hydrated didodecyl-phosphatidyl ethanolamine showing some typical bicontinuous cubic phases. (Adapted from Seddon et al, 1990 see this reference for the indicated crystallographic nomenclature.)...

Figure 21 Plot of Li concentration versus distance across a large quartz porphyroclast from the Santa Catalina mylonite zone, California. Solid symbols are parallel to the c-axis open symbols are perpendicular to it. The systematic decrease in Li content towards rim is interpreted to reflect diffusive loss to an intergranular fluid that was depleted in Li. Inset shows sketch of quartz grain in thin section and analyses C and arrows indicate crystallographic orientation of c-axis (source Hervig and Peacock, 1989).

Figure 1 Investigated molecular interstitial structures in ice Ih. Arrows indicate crystallographic directions (c.f. Ref. 1). a) Capped trigonal (Tc) intestitial b) Uncapped trigonal (Tu) interstitial c) Bond center (Be) interstitial)...

Indices, crystallographic, 260 -261 Industrial <. Engineering Chemistry Research, 402 403 Infinitives... 

Fig. 1 Schematic representation of a crystal surface inclined at a small angle to a low-index crystallographic orientation.

Recently, the In situ Raman scattering from Fe-TsPc adsorbed onto the low Index crystallographic faces of Ag was examined and the results obtained are shown In Fig. 5 (15). On the basis of the similarities of these spectra with those obtained for the macrocycle In solution phase, as well as the polarization behavior characteristics, It has been concluded that the most likely configuration Is that with the macrocycle edge-on with respect to the surface. This Is In agreement with conclusions reached from the UV-vlslble reflectance spectra. The preferred configuration, however, may depend on the particular macrocycle, as well as on the nature of the adsorption site. 

Silicon and germanium are the most important elemental semiconductors. They have the diamond cubic structure with sp hybrid bonds. The structure of the low index crystallographic planes, the only ones to be considered here, is shown in Fig. 1. It is seen that in the ill surfaces the atoms are triply bonded to the layer below and thus have one unpaired electron (dangling bond). Each atom of the 110 surfaces also... 

Chierche et al. [110] were first to study copper underpotential deposition on poly crystalline palladium. They assigned different copper voltammetric peaks to the contributions of the different low Miller index crystallographic planes of palladium. They also proposed that copper underpotential deposition obeys a Temkin-type isotherm with a saturation charge density of 420 pC cm 2. The electrochemical response on polyfaceted palladium is observed in Figure 9.6. 

In the channeling mode, extra atoms not aligned with the array will cause extra scattering. At this time, the number of backscattered ions decreases markedly. There is more than 95% reduction in the yield of small impact parameter interaction process of Rutherford scattering, when an ion beam is well aligned with a low-index crystallographic direction of a single crystal, say for example (100) of Si. 

Using single crystals it has been shown that different low-index crystal faces see Section 20) exhibit different corrosion rates. However, the relative corrosion rate of the different faces varies with the environment and these structural effects are of little practical significance. On the other hand, the fact that polycrystal grains of different crystallographic orientation may corrode at different rates, is of some importance. 

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