Accession Number : AD0290693

Title :   Final Technical Report for November 1962,

Corporate Author : MIAMI UNIV CORAL GABLES FLA

Personal Author(s) : VORRES,KARL S.

Report Date : NOV 1962

Pagination or Media Count : 1

Abstract : The conditions for the appearance of the fluoritetype solid solution with ZrO2 have been investigated experimentally by studying sub-solidus equilibria in the binary systems composed of ZrO2 and each of CuO, Cu2O, SnO2, Ag2O, l2O, CdO, and Ga2O3. No solid-solution formation was observed. The data was correlated with all other data on binary systes with ZrO2 to determine conitions for the appearance of the fluorite phase. A plot of ionic radius versus electronegativity most effectively demonstrated tht the conditions are (1) the added oxide must have a cation radius larger than that of tetravalent Zr to be stable down to room temperature and (2) the added oxide must be somewhat more electropositive than the Zr. This then produces a more nearly ionic lattice for which the fluorite structure would be expected. Furthermore, the added oxide must be di or trivalent. Random cation plcement occurs with divalent cations and ordering is obtained with the tivalent ones. The CAF2-rare earth oxide systems in a laboratory atmosphere were studied, and ABO4 type structures were correlated. (Author)

Descriptors :   *CALCIUM COMPOUNDS, *OXIDES, *REFRACTORY MATERIALS, *ZIRCONIUM COMPOUNDS, CHEMICAL REACTIONS, COMPLEX COMPOUNDS, COPPER COMPOUNDS, CRYSTAL LATTICES, CRYSTAL STRUCTURE, DIOXIDES, FLUORIDES, HEATING, IONS, METALS, MOLECULAR STRUCTURE, PHASE STUDIES, RARE EARTH ELEMENTS, SINTERING, SOLIDS, SOLUTIONS(MIXTURES), VALENCE

Distribution Statement : APPROVED FOR PUBLIC RELEASE