THERMODYNAMIC INVESTIGATION OF CERAMIC MATERIALS AT ELEVATED TEMPERATURES
Abstract
Electromotive forces from the change of partial free energy of O in TiO varied from 100 to 5 mv after 4 hr at 1375 K. Fairly constant values of electromotive force were obtained for the reaction of 2 Zr + ZrO2 + 3 ZrCr2 equals 2 Zr3Cr3O(18 mv at 1510K and 21 mv at 1550K). The half cells were Zr/ZrO2 and Zr2/Zr/Zr3Cr3O.All the transition metals (Ta, V, Nb, Mo, Cr, and W) stabilize c-ZrO2 with TiO2 and another metal. Nb2O5 and Ta2O5 were substituted for TiO2 in 2 experiments; no c-ZrO2 was formed. Similar compounds (6ZrO2.Nb2O5 and 6ZrO2.Ta2O5) were formed in each experiment and the d values in the 2 structures coincided; some reduction occurred with the Nb2O5 but not with Ta2O5. After heating for 4 hr at 1200 C, Zr2Cr2O is present in large quantities when prepared with Cr, Zr, and Cr2O3 or Cr, Zr, and ZrO2. High purity boron phosphide, prepared from BCl3 and PH3 and degassed at 1200 K to constant weight, had a smaller residue than that stoichiometrically calculated for the expected end product, B6P.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 21, 1961
- Accession Number
- AD0255085
Entities
People
- Michael Hoch
Organizations
- University of Cincinnati