Optimization of parameters, characterization and thermal property analysis of hafnium ethoxide synthesized by electrochemical method
(School of Metallurgy and Environment, Central South University, Changsha 410083, China)
Abstract: Hafnium ethoxide was synthesized using electrochemical method. Optimization experiments were used to optimize various parameters namely Et4NBr concentration(c): 0.01-0.06 mol/L, solution temperature (t): 30-78 °C, polar distance (D): 2.0-4.0 cm and current density (J): 100-400 A/m2. The electrolytic products obtained under optimum conditions of c=0.04 mol/L, t=78 °C, D=2.0 cm and J=100 A/m2 were further isolated by vacuum distillation under 5 kPa. The product was characterized by Fourier transform infrared (FT-IR) spectra, nuclear magnetic resonance (NMR) spectra. The results indicated that the product was hafnium ethoxide. ICP analysis suggested that the content of hafnium ethoxide in the final product exceeded 99.997%. Thermal properties of the product were analyzed by TG/DTG. The vaporization enthalpy of hafnium ethoxide was found to be 79.1 kJ/mol. The result confirmed that hafnium ethoxide was suitable for the preparation of hafnium oxide by atomic layer deposition.
Key words: hafnium ethoxide; electrochemical synthesis; parameter optimization; characterization; thermal analysis