S. Gross, G. Clark
Nov 1, 1938
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0
Influential Citations
2
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Journal
Zeitschrift für Kristallographie - Crystalline Materials
Abstract
In connection with work being carried on in this laboratory upon polycomponent systems involving such salts as the hydrates of trisodium phosphate and isomorphous compounds several new unit cells have been measured and studied by X-ray diffraction methods. Such measurements are important owing to the complexity of such patterns and the possibility of change of sample during exposure due to loss of water, or interaction of the material with the carbon dioxide of the atmosphere. Then, too, variations in intensity are indicated by the diagrams of Menzel and Sahr 1 ) which might be due possibly to one of the causes noted above. This makes desirable a study of the material with the rotation camera, where such decomposition or change will be shown up as D e b y e S c h e r rer rings superimposed over the rotation pattern. Evidence is presented in this paper for a more highly hydrated trisodium phosphate than has hitherto been reported; and the structure and unit cell dimensions are reported for the dodecahydrates of trisodium phosphate and trisodium vanadate; and for the compound 2Na3VOi· NaF • 19H20, isomorphous with the corresponding phosphate which was measured by Neumann 2 ) . When supersaturated solutions of analytical grade reagent Na3POi • 12 H20 were allowed to cool slowly, long acicular friable crystals were in some cases obtained, which gave upon ignition a loss of weight of 62.8%. By comparison with the percentages of water in some theoretical hydrates listed below, it can be observed that the sample corresponds to a hydrate higher than the ordinary dodecahydrate: