Electronic Conductivity in Solid CaF2 at High Temperature

Abstract

Polarization measurements have been made on CaF2 using cells of the type Ca-Pb(1) I CaF2(s) I Fe(s) (D Xca ----0.9 and Fe(s) I CaF2(s) i Ca-Bi(1) (II) XCa --0.25 * Electrochemical Society Active Member.

Thermodynamic properties of calcium titanates: CaTiO3, Ca4Ti3O10, and Ca3Ti2O7

“…is related to the difference the chemical potential of CaO at the two electrodes: l CaO À l CaO ¼ À2FE. CaF 2 is a fluorine ion conductor, with ionic transport number greater than 0.99, at the temperatures and fluorine chemical potentials encountered in this study [20,21]. Since there was no significant solid solubility between CaF 2 , CaO, TiO 2 , CaTiO 3 , Ca 4 Ti 3 O 10 , and Ca 3 Ti 2 O 7 at the temperatures covered in this study, the compounds are present at unit activity at the electrodes.…”

Gibbs Energy of Formation of Ca3Ti8Al12O37 and Phase Relations and Chemical Potentials in the System Al2O3-TiO2-CaO

“…During the course of the investigation it was found that the composition of the complex oxide reported in the literature is incorrect. The actual compound formed inside the ternary triangle has the composition Ca 3 Ti 8 Al 12 O 37 with monoclinic unit cell (space group C*/c, Z = 8) almost identical to that ascribed earlier to CaTi 3 Al 8 O 19 . [1] Thermodynamic properties of Ca 3 Ti 8 Al 12 O 37 were then measured.…”

“…The most successful synthetic strategy involved co-precipitation and subsequent heating at a slow rate of 0.005 K s À1 to 1623 K after holding at 873 K for 86 ks. Even under the optimum synthetic conditions, pure CaTi 3 Al 8 O 19 was not obtained; small amounts of secondary phases such as Al 2 O 3 , CaAl 12 O 19 , and TiO 2 were always present. Morgan [1] did not analyze the composition of the complex oxide but relied on information from an unpublished report of Kesson and Ringwood, cited as reference 2 in their article.…”

Electrochemical Determination of the Gibbs Energy of Formation of MgAl2O4

“…22,23 There is no significant solid solubility between MgF 2 and CaF 2 . Hence, the standard Gibbs energy change for this reaction (6) is directly related to the emf of the cell by the Nernst equation:…”