Potassium crystalline structure

Solid-state polymerization of D3, initiated by 7-irradiation, has been known for a long time. The reaction proceeds according to the cationic polymerization mechanism.3,5 Solid-state anionic polymerization of hexaphenylcyclotrisi-loxane in the presence of KOH or potassium oligosiloxanolate was recently reported. The crystalline structure of the polymers obtained in high yield in the heterogenous reaction was determined.1... 

Grayish-white metal hody-centered cubic crystalline structure density 19.3 g/cm3 melts at 3,422°C vaporizes at 5,555°C vapor pressure 1 torr at 3,990°C electrical resistivity 5.5 microhm-cm at 20°C modulus of elasticity about 50 to 57 x lO psi (single crystal) Poisson s ratio 0.17 magnetic sus-ceptibilty +59 x 10-6 thermal neutron absorption cross section 19.2 + 1.0 barns (2,200m/sec) velocity of sound, about 13,000 ft/sec insoluble in water practically insoluble in most acids and alkabes dissolves slowly in hot concentrated nitric acid dissolves in saturated aqueous solution of sodium chlorate and basic solution of potassium ferricyanide also solubibzed by fusion with sodium hydroxide or sodium carbonate in the presence of potassium nitrate followed by treatment with water... 

Professor von Hevesy and Thai Jantzen separated hafnia from zirconia by repeated recrystallization of the double ammonium or potassium fluorides (20, 26). Metallic hafnium has been isolated and found to have the same crystalline structure as zirconium. A small specimen of the first metallic hafnium ever made is on permanent display at the American Museum of Natural History in New York City. Dr. von Hevesy, who prepared it, presented it to the Museum for the collection of chemical elements (29). A. E. van Arkel and J. H. de Boer prepared hafnium by passing the vapor of the tetraiodide over a heated tungsten filament (26, 30). 

Exsolution The unmixing of an initially homogeneous substance into two or more separate crystalline substances. For example, at 1000 °C and one bar pressure, sodium and potassium can readily substitute for each other in the crystalline structure of the aluminum silicate mineral alkali feldspar to form (Na,K)AlSi30g. At much lower temperatures, the sizes of the sodium and potassium atoms are too dissimilar for the crystalline structure to remain stable and the alkali feldspar separates (exsolves) into NaAlSisOg and KAlSisOg components (Klein, 2002), 143. 

Iron (at room temperature), titanium (at high temperatures), molybdenum, niobium, potassium, tungsten, and vanadium have body-centered cubic crystalline structures. 

Potassium tellurides.—The monotelluride, K2Te, was originally produced by Davy12 by direct combination of the elements. At 250° C. the reaction is even more energetic than that between sodium and tellurium. When prepared in an atmosphere of hydrogen, the product has a crystalline structure, and a dark iridescent-purple colour. With water it yields a purple solution, being reprecipitated by alcohol in the form of small, ill-defined crystals.18... 

Figure 2(C) is the result of a calculation that illustrates which cations might fit into sixfold coordination position in the calcite group structures. It is an interesting insight as both light and heavy rare earth elements are possible substitutes for calcium in the calcium carbonate structure, i.e., they plot within 15% of the calcium ionic size. However, some of the end-members incorporate elements into this crystal structure and are outside this deviation but within 30%, an expression of the potential physical expansion for this layered crystal structure. These are ionic charge differences important in whether a stable crystalline structure can be produced. Trace amounts of all these ions can be incorporated in calcite and may dictate the morphology of the crystallites. Therefore, the presence and amount of any ions in the environment in which carbonate crystallization occurs may possibly be recorded. However, in spite of the predominance of sodium and potassium in the solutions where...

The effect of fillers on smoke suppression depends on the particle size and crystalline structure of the filler. A new fire retardant, based on a hydrated potassium-magnesium aluminosilicate, in two grades - coarse and fine is available. The fine grade is twice as effective as the coarse grade. ... 

Electron microscopy of and a study of electron dilBfraction by a thin film of the complex formed between copper phthalocyanine and potassium have revealed a unique crystalline structure/ The electron micrographs showed that an island film structure existed, with single crystals of the complex being up to 1 /utm in diameter. The films were stable in vacuo, but on exposure to air they degraded over a period of 24 hours, after which only traces of the ordered structure were observable by electron diffraction. 

Ammonium nitrate-containing pyrotechnic gas-generating formulations may suffer from phase changes in a crystalline structure associated with volumetric expansion during temperature cycling. Potassium nitrate and cupric oxide have a synergistic effect in stabilizing ammonium ni-... 

Mica is a generic name to describe a group of complex hydrous potassium aluminate silicate materials, differing in chemical composition, but sharing a unique laminar crystalline structure. In nature, mica develops in a book-like form. The individual platelets can be delaminated into very thin high aspect ratio particles that are tough and flexible. Of the commercially important forms, muscovite and phlogopite are used as reinforcements for plastics. 

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