D-A crystal

Fig. 5. A donor impurity is diffused into the silicon from a gaseous phase, (a) A shallow n region lias been created, (b) Continued diffusion, longer times, or higher temperatures increase the extent of the n region, (c) Surface diffusion has caused spreading of the n region along the SiCVsilicon interface, (d) A crystal defect, such as a dislocation, has provided a path for anomalously high diffusion and led to penetration of the junction to unanticipated distance from the surface. (See Fig. I for legend)...

Figure 2.36. Example of cleavage and fracture at the atomic (a, b) and macroscopic (c, d) levels. In images (c, d), a crystal of NaQ is exposed to a stress along an oblique angle to the cleavage plane, resulting in both cleavage and fracturing. Images taken with permission from the Journal of Chemical Education online ...

FIGURE 2.8. Some methods for growing crystals from solution, (a) Slow solvent evaporation, primarily used for small molecules, (b) Vapor diffusion, (c) The hanging drop method, primarily used for macromolecules, (d) A crystallization plate used for hanging drops there are slightly different crystallization conditions in each well, varied systematically with respect to, for example, pH and ionic strength. 

FIGURE 2,12. The indexing of crystal faces, (a) The derivation of the integers used to describe the crystal faces (Miller indices). The (213) face is marked as an example. It intersects the axes of the unit cell at a/2, 6/1, and c/3. (b) Several parallel planes can be represented by these Miller indices. They intersect at, for example, a, 26, 2c/3 3a/2, 36, c. (c) A crystal with its (100) face (stippled), intersecting the x tixis at x = a and the y and z axes at infinity (that is, parallel to them), (d) A crystal with a (213) face stippled,... 

FIGURE 7.7. Methods of mounting crystals, (a) A crystal mounted in a glass fiber, as used for a small-molecule crystal that does not decompose on exposure to air. (b) Diagram of the mounting of a crystal in a capillary tube, (c) and (d). A crystal of a chemically modified horse hemoglobin enclosed with mother liquor in a thin walled glass capillary. (Courtesy J. J. Stezowski). 

FIGURE 3.1 Crystals of a variety of macromolecules. In (a), clusters of needle crystals of bacterial a amylase in (b), crystals of a protease from pineapple, in (c), a crystal of satellite tobacco mosaic virus and in (d), a crystal of the sweet protein thaumatin. 

Figure 8.21 Schematic representations of normal and modulated crystal structures and diffraction patterns (a) a normal superlattice, formed by the repetition of an anion substitution (b) part of the diffraction pattern of (a) (c) a crystal showing a displacive modulation of the anion positions (d) a crystal showing a compositional modulation of the anion conditions, (the change in the average chemical nature of the anion is represented by differing circle diameters) (e) part of the diffraction pattern from (c) or (d) (f) a modulation wave at an angle to the unmodulated component (g) part of the diffraction pattern from (f). Metal atoms are represented by shaded circles and non-metal atoms by open circles...

Famham, W.B. Smart, B.E. Middleton, W.J. Calabrese, J.C. Dixon, D.A. Crystal and molecular structure of tris(dimethylamino)sulfonium trifluoromethoxide. Evidence for negative fluorine hyperconjugation. J. Am. Chem. Soc. 1985, 107, 4565. 

Tettenhorst R.T., Hoffmann D.A. Crystal chemistry of boehmite. Clays Clay Miner. 1980 28 373-380... 

FIGURE 2.2 Radial distribution functions for [a] a hard sphere fluid, [b] a real gas, (c) a liquid, [d] a crystal. 

Mulliken symbols The designators, arising from group theory, of the electronic states of an ion in a crystal field. A and B are singly degenerate, E doubly degenerate, T triply degenerate states. Thus a D state of a free ion shows E and Tj states in an octahedral field. 

Fig. Vn-2. Conformation for a hypothetical two-dimensional crystal, (a) (lO)-type planes only. For a crystal of 1 cm area, the total surface firee energy is 4 x lx 250 = 1000 eigs. (b) (ll)-type planes only. For a crystal of 1-cm area, the total surface free eneigy is 4 x 1 x 225 = 900 ergs, (c) For the shape given by the Wulff construction, the total surface free energy of a 1-cm crystal is (4 x 0.32 x 250) + (4 x 0.59 x 225) = 851 ergs, (d) Wulff construction considering only (10)- and (ll)-type planes.

Fig. VII-7. Motion of an edge dislocation in a crystal undeigoing slip deformation (a) the undeformed crystal (b, c) successive stages in the motion of the dislocation from right to left (d) the undeformed crystal. (From Ref. 113 with permission.)...

Figure B3.2.12. Schematic illustration of geometries used in the simulation of the chemisorption of a diatomic molecule on a surface (the third dimension is suppressed). The molecule is shown on a surface simulated by (A) a semi-infinite crystal, (B) a slab and an embedding region, (C) a slab with two-dimensional periodicity, (D) a slab in a siipercell geometry and (E) a cluster.

Vanden Bout D A, Kerimo J, Higgins D A and Barbara P F 1996 Spatially resolved spectral inhomogeneities in small molecular crystals studied by near-field scanning optical microscopy J. Chem. Phys. 100 11 843-9... 

Fig. 1. (a) Silicon (valence = 4) crystal lattice shown in two dimensions with no broken bonds, T = 0 K (b) siUcon crystal lattice with a broken bond (c) sibcon crystal lattice with a siUcon atom displaced by a donor dopant, ie, -doped (valence = 5) and (d) siUcon crystal lattice with a siUcon atom displaced... 

Fig. 12. General stmcture of LCD. A, polarizer plate B, glass plate C, electrodes (indium—tin oxide) D, Hquid crystal E, common electrode (ITO) F, overcoated layer G, colored pixel H, back light. In an improved color LCD system today, retardation films are placed between A and B.

Goldman, A., Ollis, D.L., Steitz, T.A. Crystal structure of muconate lactonizing enzyme at 3 A resolution. 

Bode, W., et al. The refined 1.9 A crystal structure of human a-thrombin interaction with D-Phe-Pro-Arg chloromethylketone and significance of the Tyr-Pro-Pro-Trp insertion segment. EMBO ]. 8 3467-3475,... 

Fremont, D.H., Matsumura, M., 5tura, E.A., Peterson, P.A., Wilson, I.A. Crystal structures of two viral peptides in complex with murine MHC class I H2-K . Science 257 919-927, 1992. 

Figure 7.4 Microcomputer programming of a hatch cooling crystallizer. A, crystallization vessel, B, control heater, C, control cooler. surrounding the draft-tube), D, contact thermometer, E, discharge plug and conical baffle), F, recorder, G, relay, H, temperature programmer, I, cooling water pump, J, cooling water reservoir, K, water inflow L, water outflow after Jones and Mullin, 1974)...

Beckmann, J.R. and Randolph, A.D., 1977. Crystal size distribution and dynamics in a classified crystallizer. Part II. Simulated control of crystal size distribution. American Institution of Chemical Engineers Journal, 23, 510-520. 

Bennett, R.C., Fiedelman, H. and Randolph, A.D., 1973. Crystallizer influenced nuclea-tion. Chemical Engineering Progress, 69, 86. 

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