Thermal Behavior of Mixtures of Zirconium(IV) and Yttrium(III) Dipivaloylmethanates

The thermal properties of individual precursors, zirconium(IV) and yttrium(III) dipivaloylmethanates, and of their mixtures [Zr(thd)₄–Y(thd)₃, Hthd = 2,2,6,6-tetramethylheptane-3,5-dione] used for preparing mixed oxide films by chemical vapor deposition were studied in the condensed and gas phases. In the condensed phase, the vaporization rate of both individual compounds and their mixtures considerably exceeds the decomposition rate. The vaporization, thermal stability of the vapors, and thermal decomposition of the compounds in a vacuum and in the presence of oxygen were studied using mass-spectrometric monitoring of the gas phase composition. Comparison of the thermal behavior of individual Zr(thd)₄ and Y(thd)₃, heated in separate vaporizers of the mass spectrometer inlet system, and of their mixtures with different Zr(thd)₄ to Y(thd)₃ ratios reveals no chemical interaction between the precursors in the examined temperature interval.