Author: M. M. NakataPublisher:
ISBN:
Category : Vaporization, Heats of
Languages : en
Pages : 32
Book Description
Vaporization of Zirconium Oxide
Author: M. M. NakataPublisher:
ISBN:
Category : Vaporization, Heats of
Languages : en
Pages : 32
Book Description
VAPORIZATION OF ZIRCONIUM OXIDE.
Author: The Vaporization Behavior and Thermodynamic Stability of Zirconium Carbide at High Temperature
Author: B. D. PollockPublisher:
ISBN:
Category : Thermodynamics
Languages : en
Pages : 24
Book Description
The Influence of Pressure and Temperature on Zirconium Oxide
Author: F. W. VahldiekPublisher:
ISBN:
Category : Temperature
Languages : en
Pages : 42
Book Description
Thermodynamic Properties of Some Metal Oxide-zirconia Systems
Author: Nathan S. JacobsonPublisher:
ISBN:
Category :
Languages : en
Pages : 66
Book Description
Metal oxide-zirconia systems are a potential class of materials for use as structural materials at temperatures above 1900 K. These materials must have no destructive phase changes and low vapor pressures. Both alkaline earth oxide (MgO, CaO, SrO, and BaO)-zirconia and some rare earth oxide (Y2O3, Sc2O3, La2O3, CeO2, Sm2O3, Gd2O3, Yb2O3, Dy2O3, Ho2O3, and Er2O3)-zirconia system are examined. For each system, the phase diagram is discussed and the vapor pressure for each vapor specie is calculated via a free energy minimization procedure. The available thermodynamic literature on each system is also surveyed. Some of the systems look promising for high temperature structural materials.
High Temperature Thermodynamics and Vaporization of the Zirconium--niobium--oxygen System
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The vaporization behavior of the Zr--Nb--O system was studied by means of successive vaporization, Knudsen effusion-target collection experiments, and mass spectrometric analysis of the vapors effusing from a Knudsen crucible. The successive vaporization experiments were performed on two ternary samples in open crucibles. X-ray powder diffraction patterns of the residues and x-ray fluorescence analysis of the condensates and residues indicated the preferential vaporization of niobium-containing species with the composition of the residue subsequently becoming closer to that of congruently vaporizing ZrO/sub 2-x/. The Knudsen effusion-target collection experiments were employed on two samples, pure NbO2(s) and a two-phase ZrO2--NbO2 mixture, in order to obtain information on the activity of NbO2 in the two-phase mixture. Second law enthalpies and entropies of sublimation as well as third law enthalpies were obtained for both systems. The vaporization behaviors of five compositions in the Zr--Nb--O system, NbO2, NbO, a ZrO2--NbO2 two-phase mixture, Nb2O5, and Zr6Nb2O1--, were investigated. Above Nb2O5 and the fully oxidized Zr6Nb2O1-- oxygen is preferentially lost; over NbO2, the two-phase ZrO2--NbO2 system, and NbO the principal gaseous species is NbO2.
The Chemical Vapor Deposition of Zirconium Dioxide from Zirconium Tetra-tert-butoxide and Zirconium Nitrate
Author: David Jeffrey BurlesonPublisher:
ISBN:
Category :
Languages : en
Pages : 438
Book Description
Vapor Pressures of Zirconium Tetrachloride and Hafnium Tetrachloride
Author: D. W. KuhnPublisher:
ISBN:
Category : Hafnium tetrachloride
Languages : en
Pages : 46
Book Description
VAPOR PRESSURES OF INORGANIC SUBSTANCES: ZIRCONIUM DIOXIDE.
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 17
Book Description
The Knudsen effusion method was used to measure the vapor pressure of ZrO2 and a stoichiometric ZrO2+Zr mixture between 2014 and 2290 K. The pressure was calculated from rate of effusion data, using the equation p=m square root of 2 pi RT/M (p is the pressure in atmospheres; m, the rate of effusion in g/sq cm/sec; R, the molar gas constant; and M, the mol wt of the vapor). The same rates of evaporation in both cases indicated that ZrO2 vaporizes as ZrO2. The mean heat of evaporation (140.3 + or - 1.5 kcal) of ZrO2 was determined from the slope of the log p vs 1/T plot for the stated temperature range. By using a previously determined heat of evaporation for Zr and delta H sub f of ZrO2(s) (NBS values), 375 + or - 5 kcal/mol was obtained for the heat of dissociation for ZrO2 (g) into Zr (g) and O (g). The bp pf ZrO2 was calculated to be 3735 K from the NBS data for temperature, heat, and entropy of fusion. (See also AD18365).
Author: You-Sheng Lin