The high temperature vaporization and thermodynamics of the titanium oxides. XII. The temperature coefficient of the vapor pressure of TiO

摘要

Knudsen vapor pressure measurements over the temperature range 1921ndash;1998 K are reported for stoichiometric titanium monoxide contained in a molybdenum crucible. The pressures are consistent with that obtained in the preceding paper at 1806 K with the same material in a tungsten crucible. The combined results are given by logPE(atm) = (minus;129.2plusmn;1.7) times;103/4.576T+(39.25plusmn;0.86)/4.576. The uncertainties should be increased by about a factor of 3 to recognize the uncertainties in the mass spectrometric ionization cross sections. This equation together with the Knudsen equation allows the calculation of the equilibrium rate of mass loss of incongruently vaporizing stoichiometric TiO over the range zero to about 8percnt; mass loss.