Vapor Pressure Measurements of Sc(tmhd)₃ and Synthesis of Stabilized Zirconia Thin Films by Hybrid CVD Technique Using Sc(tmhd)₃, Zr(tmhd)₄, and Al(acac)₃ [tmhd, 2,2,6,6-tetramethyl-3,5-heptanedione; acac, 2,4-pentanedione] as Precursors

Abstract

The congruent vaporization of Sc(tmhd) 3 was verified from the molar mass of the vapor species obtained using ESI-mass spectra and thermogravimetry. On the basis of the molar mass so obtained, the equilibrium vapor pressures over a temperature span of 375−465 K, determined by adapting a tested horizontal dual arm single furnace thermoanalyzer as a transpiration apparatus, gave values of 97 ± 1 and 77 ± 2 kJ mol −1 for the standard molar enthalpies of sublimation and vaporization, respectively, for Sc(tmhd) 3. . The vapor pressure and enthalpy results of benzoic acid were found to be in good agreement with the reported data. A hybrid chemical vapor deposition process is described for reproducible solid electrolyte thin films of scandia-stabilized zirconia or alumina-doped ScSZ. The process uses a single solution source of Sc, Zr, and Al β-diketonates dissolved in triglyme. Experimental details of this process are described, and the effects of different process parameters are studied in order to improve the quality of the deposited layers.