Evaluation of enthalpy of sublimation of Zr(tmhd) 4 by using thermogravimetric transpiration method

The metallo-organic chemical vapour deposition (MOCVD) of ZrO 2 films is promising in various technological fields. Zr(tmhd) 4, tetrakis(2,2,6,6-tetramethyl-3,5-heptanedionato)zirconium(IV), has been identified as an ideal precursor. The thermal stability and complete volatility of the synthesized zirconium precursor were inferred from the thermogravimetric analysis. The monomeric structure of the complex was confirmed by electron spray-ionization mass spectroscopy. The vapour pressure measurement was carried out by TG-based transpiration technique and the enthalpy of sublimation was calculated from the slope of Clausius–Clapeyron equation. This yielded a value of 85.36 (± 3.60) kJ mol − 1 for the standard enthalpy of sublimation over the temperature span of 411–463 K.