P-quartz

Crystal phase is P-quartz ZrTiO unless otherwise noted. Corning. 

Fig. 5. Relative change in length with temperature of P-quartz glass-ceramics designed for A, precision optics and B, cooktop panels. Curves for C, fused...

H.S.S. High sulfidation system L.S.S. Low sulfidation system Q.P. Quartz porphyry... 

Different modifications of a compound are frequently designated by lower case Greek letters a, j3,..., e.g. a-sulfur, j3-sulfur, or by roman numerals, e.g. tin-I, tin-II etc. Polymorphic forms of minerals have in many cases been given trivial names, like a-quartz, P-quartz, tridymite, cristobalite, coesite, keatite, and stishovite for Si02 forms. 

P-parinaric acid, physical properties, 5 33t P-pentenoic acid, physical properties, 5 3 It P-peroxylactones, 18 484 Beta phase titanium, 24 838 in alloys, 24 854-856 properties of, 24 840, 941 P-phellandrene, 24 493 P-picoline, 21 110 from acrolein, 1 276 uses for, 21 120 P-pinene, 3 230 24 496-497 major products from, 24 478 /-menthol from, 24 522 as natural precursor for aroma chemicals, 3 232 terpenoids from, 24 478-479 P-propiolactone, polymerization of, 14 259 P-quartz solid solution, 12 637—638 Beta ratio, in filtration, 11 329—330 Beta (P) rays, 21 285 P-scission reactions, 14 280-281 P-skytanthine, 2 101 P-spodumene solid solution, 12 638-639 P-sulfur trioxide, 23 756 P-sultones, 23 527 P-tocopherol, 25 793 P-tocotrienol, 25 793 P-vinylacrylic acid, physical properties, 5 33t... 

Silicon itself crystallizes with the same structure as diamond. Its normal oxide, silica, Si02, is polymorphic and in previous sections we have discussed the crystal structure of two of its polymorphs—P-cristobalite (Section 1.5.2) and P-quartz ... 

Schott Zerodur p-quartz solid solution, Si02 zero expansion electric range tops, telescope mirrors... 

Corning 9632b p-quartz low expansion, high strength, thermal stability, chemical durability electric range tops (transparent)... 

Coming 9606 cordierite, 2 MgO-2 Al203-5 Si02 spinel, Mg0Al203 MgO-stuffed p-quartz quartz, Si02 low expansion, high transparency to radar missile radomes... 

Glass-ceramics containing p-quartz or p-spodumene can be made from glass of the same composition by modifying its heat treatment p-quartz is formed by ceramming at or below 900°C, and p-spodumene by ceramming above 1000°C. 

Fig. 6. Microstructure of transparent p-quartz solid solution glass-ceramic as...

The structure of p-quartz is unique and much different from those of tridymite and cristobalite. It does not follow the rules for the PTOT system, but the notation can be applied with some qualification. In general, for close-packed structures between packing layers there are two T layers, and half way between the P layers there is an O layer. The... 

FIGURE 7-22 Crystal Structure of P-Quartz. (a) Overall structure, showing silicon atoms only. 

F. Langenhorst and A. Deutsch, Shock experiments on pre-heated a- and p-quartz 1. Optical and density data. Earth Planet. Sci. Lett. 125, pp. 407-420 (1994). 

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