Ammonium dihydrogen phosphate crystal

The use of Eq. (3.24) is illustrated in Figure 3.22, where the measured face growth rates of ammonium dihydrogen phosphate crystals are plotted against the inverse of the concentration of impurities (AICI3 and FeCl3). Both sets of data are consistent with Eq. (3.24), which predicts vi = 0 at high impurity concentration... 

Figure 6.6. An elliptical spiral on the (100) face of an ammonium dihydrogen phosphate crystal growing in aqueous solution Davey and Mullin, 1974)...

Davey, R. J., and Mullin, J. W. 1974. Growth of the 100 faces of ammonium dihydrogen phosphate crystals in the presence of ionic species. J. Cryst. Growth 26 45. 

Because of the relatively large dispersion from the electrons compared with the almost constant refractivity of the neutrals and the negligible contribution of the ions, it is possible, with simultaneous measurements at two different wavelength, to determine independent values of the density of electrons and of the nonelectronic components in the plasma 274). Alcock and Ramsden 275) used the light from a giant-pulse ruby laser and its second harmonic generated in an ADP-crystal (ammonium dihydrogen phosphate) to probe a pulsed plasma and its time-dependent density in a Mach-Zehnder interferometer. 

In addition to natural quartz. Rochelle salts, and tourmaline, synthetic crystals, such as ethylenediamine tartrate (EDT), dipotassium tartrate (DKT), and ammonium dihydrogen phosphate (ADPj have varying suitability as piezoelectric elements. While Rochelle salt has a greater piezoelectric effect than any other crystal, it has the disadvantage uf a greater sensitivity to temperature change than quartz. EDT has an advantage over quartz when used in frequency-modulated oscillators because of... 

Phosphoramidic acid forms colorless, prismatic crystals the x-ray diffraction2 and infrared absorption4 data have been reported. The compound is easily soluble in water, but the aqueous solution hydrolyzes to ammonium dihydrogen phosphate. It is stable in sealed containers, but it converts on heating to an ammonium polyphosphate.5 An unstable monohydrate of phosphoramidic acid has been described.2... 

The Pockel s cell used by Grosjean and Legrand [2] is based on the above principle and is composed of a Z cut section of a single crystal of ammonium dihydrogen phosphate. A diagram of a Pockel s cell is shown in figure 5. 

When transparent electrodes (glycol windows) are placed on either side of the crystal of ammonium dihydrogen phosphate and linearly polarized light, oriented at 45° to the crystallographic axis, is... 

FIGURE 1.3. Crystals of (a) quartz, and (b) ammonium dihydrogen phosphate. Note the symmetry of face development, especially in (b). 

Most commonly, factors such as rapid crystal growth and uneven levels of supersaturation across the crystal interface are related to the formation of inclusions. The formation of inclusions in the crystals of ammonium dihydrogen phosphate (NH4H2PO4) and sodium chlorate (NaClOs) crystals have, for example, been correlated with sudden step changes in supersaturation (Brooks et al. 1968). Thus, it appears likely that nonuniform concentration and temperature in industrial crystallizers can also promote the formation of inclusions. 

I lore, dOldk, a measure of dispersion, is seen to be inversely proportional to d. Table 12-3 provides disper-sion. aia for the various crystals at their maximum and niininflim wavelengths. The low dispersion of ammonium dihydrogen phosphate prohibits its use in the region of short wavelengths here, a crystal such as topar or lithium fluoride must be substituted. 

Small amount of impurities sometimes retard dramatically the crystal growth rate. Chromium(III), for example, suppresses the crystal growth of potassium sulfate(i), ammonium dihydrogen phosphate(2) and ammonium sulfate (5), etc. in aqueous solutions. Other metallic ions, iron(III), aluminium(III) are also effective impurities W... 

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