Maximum crystal size

The transparency requirement quoted above immediately sets a limit on the maximum size of the nonlinearity we can expect to find in such materials. Data for known nonlinear crystals implies that it is unlikely to find crystals with phase-matchable d coefficients much greater than 2 pm/V if their UV edge is shorter than 250 nm. Although the size of the d coefficients is bounded by the transparency requirement, threshold powers substantially smaller than those of KDP can still be... 

Fig. 1.8. (a) Photographs of a hydrothermally grown zinc oxide single crystal (Mineral Ltd., Alexandrov, Russia) and (b) of zinc oxide wafers prepared from such crystals (Crystec GmbH, Berlin, Germany). The as grown crystal in (a) has a maximum size of 70 mm [73]. The size of the crystals in (b) is 10 x 10 x 0.5 mm3... 

Figure 6 Cosmic jewels an aggregate of tiny blue hibonite crystals from the Murray CM chondrite. This entire object is no more than 100 xm in maximum size. The color of these sapphire-like gems is real and is due to the presence of substantial titanium in the crystal structure. The color variation is partly due to the crystals being compositionaUy zoned (their margins are more titanium-rich), and also to their being pleochroic under plane polarized light the color is visible only when the crystals are in specihc orientations relative to the polarizers on the...

The maximum size of the unit cell edges can be estimated from the d-spacing of the first Bragg peak (t/max) observed in the diffraction pattern. In the majority of low symmetry cases (triclinic through orthorhombic crystal systems), the maximum size of the unit cell edge should not exceed... 

Maximum scattering occurs when the droplet size is on the order of the wavelength of light. The liquid crystal droplet size is altered by warming the films to form a homogeneous solution, followed by cooling at a controlled rate. Table II lists droplet size as a function of cooling... 

The freezing process influences the building of the phases of ice, air and fat. The maximum size of ice crystals may not exceed 60 pm, otherwise the crystals could be detected by the consumer. 

Detectors with a functional surface of over 10 cm in diameter are currently available on the market. Since the end of the 1990s, they are custom-made on diffractometers designed for stmctural studies of single crystals. This maximum size, a technical feat for the manufacturers that justifies a very high price, is a significant limitation to the use of these detectors for diffraction on polycrystalline samples. As we will see later on, prototypes of diffractometers designed for the study of polyciystalline samples and equipped with this type of detector have recently been produced. 

Sweetened condensed milk is supersaturated with lactose, and the lactose crystals formed tend to settle and also give the product a sandy mouth feel. To prevent this, crystal size should be at most 8 pm, and one generally tries to achieve this by adding crystalline seed lactose, about 0.3 g per kg product. Calculate what the maximum size of the seed particles may be. One kg of sweetened condensed milk contains about 110 g lactose, 440 g sucrose, and 260 g water. Consult also Table 2.2. 

Colloidal offretite crystals with a maximum size of up to 250 nm were prepared by hydrothermal synthesis at 100°C. The system is unusual in the sense that colloidal crystals form from a gel and that the yield sometimes is very high. The effects of the duration of hydrothermal treatment and the composition of the synthesis mixture on the product were investigated using XRD, DLS and SEM. Some syntheses resulted in mixtures of offretite and amorphous material or colloidal sodalite, whereas others resulted in a pure and colloidal offretite product. 

Unlike their crystal-orbital counterparts, the finite-cluster calculations carried out in conjunction with extrapolations are free from the problems associated with the reciprocal space integration. Their accuracy can be easily monitored by increasing the maximum size of clusters and comparing the values of properties calculated with different extrapolation methods. The termi-... 

The electrolysis have been carried out at the temperature 720-780 C, Dc=0.2-0.5 A/cm. The NbO-anod was used. An external view of the crystals obtained on cathode is shown in Fig.l. The crystals are formed into a blocks of rectangular tables with maximum size of single crystal 0.5x0.5x0.05 mm. They are dark grey in colour and have a metallic lustre. 

X-ray diffraction is also useful in investigating the order in nematic liquid crystals. The size of the molecule itself implies that there should be a slight variation in the density, with the spatial period being roughly a molecular length along the director and roughly a molecular width perpendicular to the director. The motion of the molecules ensures that these periodicities are very small, but they should produce a diffuse maximum in the... 

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