Thermal study of CVD metal–organic precursors
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The pressure of the saturated and unsaturated vapors of Zr(thd)4 and Y(thd)3 (thd = 2,2,6,6-tetramethyl-3,5-heptanedionate) has been measured by the static method with a membrane-gauge manometer in a wide interval of temperatures: 473–623 K for Zr(thd)4 and 424–605 K for Y(thd)3. As a result of this study, the thermal stability of compounds under study was reliably established. From the unsaturated vapor data, it was concluded that Zr(thd)4 passes into a gas phase as a monomer up to its decomposition while gas phase over Y(thd)3(cond) contains some polymers. Equations approximating the dependences of saturated vapor pressure on temperature and also the enthalpies and entropies of sublimation [Zr(thd)4, Y(thd)3] and vaporization [Y(thd)3] were obtained. The thermal behavior of the complexes was also investigated by differential scanning calorimetry, and the thermodynamic parameters of phase transitions (Ttr, ΔtrH Ttr ° ) were determined. Obtained information was compared with previous published data.
KeywordsZirconium and yttrium beta-diketonates Static method with a membrane-gauge manometer Scanning calorimetry Enthalpy Entropy
This work was partially funded by Russian Scientific Foundation according to the research Project No. 16-19-10325. We also thank Federal Agency for Scientific Organizations for funding.
- 1.Hitchman ML, Jensen KF, editors. Chemical vapor deposition: principles and applications. London: Academic; 1993.Google Scholar
- 2.Syrkin VG. CVD method. Chemical vapor-phase deposition. Moscow: Nauka; 2000 (in Russian).Google Scholar
- 11.Peshkova VM, Mel’chakova NV. β-Diketony (β-diketones). Moscow: Nauka; 1986 (in Russian).Google Scholar
- 13.Mishin VY, Solov’ev SM, Chimenov PP, Voronin AS, Kapitonov VI, Rubcov EM, Soloschenkov PS, Isupov VK, Prokoptschuk YZ. Volatile β-diketonates of actinides and some possibilities of their practical use. Radiokhimiya. 1985;27:354–61 (in Russian).Google Scholar
- 15.Gubareva AI, Gerasimov PA, Morozova NB, Fedotova NE, Igumenov IK. Termokhimicheskie svoistva tetrakis-dipivaloilmetanata zirkonia(IV). Zh Prikl Khim. 1993;66:907–10 (in Russian).Google Scholar
- 24.Konstantinov SG, Dudchik GP, Korsun VP, Polachonok OG, Kostromina NA. Volatility and thermal stability of rare earth dipivaloylmethanates. In: Spitsyn VI, editor. Probl. Khim. Primen. β-Diketonatov Metallov. Moscow: Nauka; 1982. p. 143–5 (in Russian).Google Scholar
- 29.Eisentraut KJ, Sievers RE, Coucouvanis D, Fackler JP. Volatile rare-earth chelates of 2,2,6,6-tetramethylheptane-3,5-dione. In: Jolly WL, editor. Inorganic syntheses, vol. 11. New York: McGraw-Hill Book Co; 1968. p. 94–8.Google Scholar
- 32.Suvorov AV. Thermodynamic chemistry of the vapor state. Leningrad: Khimija; 1970 (in Russian).Google Scholar
- 34.Girichev GV, Giricheva NI, Belova NV, Kaul AR, Kuz’mina NP, Gorbenko OY. Study of thermal stability of yttrium dipivaloylmethanate by mass spectrometry. Zh Neorg Khim. 1993;38:342–5 (in Russian).Google Scholar
- 36.Titov VA, Kokovin GA. In: Kokovin GA, editor. Mathematics in chemical thermodynamics. Novosibirsk: Nauka; 1980. p. 98–105.Google Scholar