Accession Number : AD0681671

Title :   ISOMORPHISM IN BINARY SYSTEMS OF DIVALENT METAL TUNGSTATES,

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Tombak,M. I. ; Demyanets,L. N. ; Lapsker,Ya. E.

Report Date : 28 MAR 1968

Pagination or Media Count : 16

Abstract : X-ray phase analysis and a study of the optical characteristics were used to investigate mutual solubility in two-component systems formed by CaWO4 with tungstates of other divalent metals: MgWO4, ZnWO4, SrWO4, PbWO4 and BaWO4. The formation of a continuous series of mixed crystals in the CaWO4-SrWO4 system was established, and an unlimited miscibility in the CaWO4-PbWO4 system was confirmed. It is shown that in the CaWO4-BaWO4 system a limited solubility is observed at low concentrations of one of the components, whereas in the CaWO4-MgWO4 and CaWO4-ZnWO4 systems no solid solutions are formed over the entire concentration range. Excitation and luminescence spectra of these systems were obtained, and it was found that the character of the excitation spectra can be used to evaluate the phase composition of the system: in the presence of two phases, the spectrum consists of two clearly distinguishable bands. However, emission spectra do not constitute an unequivocal characteristic in studies of isomorphous substitution. (Author)

Descriptors :   (*TUNGSTATES, *SOLID SOLUTIONS), CALCIUM COMPOUNDS, BARIUM COMPOUNDS, LEAD COMPOUNDS, MAGNESIUM COMPOUNDS, STRONTIUM COMPOUNDS, ZINC COMPOUNDS, SOLUTIONS(MIXTURES), CRYSTAL STRUCTURE, X RAY DIFFRACTION, EXCITATION, LUMINESCENCE, PHASE STUDIES

Subject Categories : Physical Chemistry
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE