Thermodynamic Study of a Volatile Complex of Magnesium Benzoyltrifluoroacetonate with N,N,N',N'-Tetramethylethylenediamine

Abstract

To expand the library of volatile magnesium precursors certified for effective use in chemical gas-phase deposition of the corresponding oxide or fluoride layers, a thermodynamic study of the mixed ligand complex Mg(tmeda)(btfac)2 (tmeda is N,N,N',N'-tetramethylethylenediamine, btfac is benzoyl trifluoroacetonate) have been performed. The melting process has been studied using DSC (Tm = 459.4 ± 0.3 K,= 42.9 ± 0.4 kJ/mol); the sublimation process has been studied using the flow (transfer) method in the temperature range 407–447 K (= 163 ± 6 kJ/mol, ΔsublS427 = 293 ± 14 J/(mol K)). The substance passes into the gas phase with partial decomposition. Thermodynamic modeling of the composition of condensed phases formed from Mg(tmeda)(btfac)2 with the addition of H2 or O2 has been performed depending on the temperature (700–1300 K), total pressure (133–13 332 Pa), and the ratio of the reagent gas to the precursor (0–300). The data obtained can be used to determine the experimental parameters of the processes for obtaining functional layers. Comparison of the results with a similar trifluoroacetylacetonate complex made it possible to quantitatively reveal the effect of replacing the methyl group in the anionic ligand with a phenyl one.