Dimeric titanyl bis(tert-butyl-2-oxobutanoate) (or oxotitanium bis(tert-butylacetocetate)) [TiO(tbob)2]2 was reported to be useful as MOCVD precursor for Ti-containing layers. Vapour pressure and enthalpy
of sublimation of TiO(tbob)2 (and for comparison its titanium bis(isopropoxide) analogue Ti(OiPr)2(tbob)2) was determined
by variable temperature thermogravimetric/differential thermogravimetric (TG/DTG) analysis, and [TiO(tbob)2]2 was evaluated as potential MOCVD precursor for the growth of Ti-contaning layers. The complex [TiO(tbob)2]2 was found to be less suitable as titanium MOCVD precursor compared to Ti(OiPr)2(tbob)2.[i]
[i] G.V. Kunte, S.A. Shivashankar, A.M. Umarji, Meas. Sci. Technol., 2008, 19, 025704, doi:10.1088/0957-0233/19/2/025704, « Thermogravimetric evaluation of the suitability of precursors for MOCVD », http://iopscience.iop.org/0957-0233/19/2/025704
Bis(ethyl-3-oxo-butanoato)oxotitanium(IV) [TiO(etob)2]2, a novel volatile stable oxo-β-ketoesterate complex of titanium, was synthesized through a straightforward synthesis and characterized; various spectroscopic techniques have been used to confirm the structure (dimeric [TiO(etob)2]2). The thermal properties of TiO(etob)2]2 were studied by thermogravimetric analysis.
[TiO(etob)2]2 was applied as precursor for the growth of TiO2 films by low-pressure MOCVD at temperatures 400-525 °C on glass substrates. The morphology of the grown layers was studied by TEM, SEM,
AFM and electron diffraction; all TiO2 films grown in this temperature range were very smooth. However, layers grown >480°C consisted of almost monodisperse anatase phase nanocrystals. The bandgap 3.4–3.7 eV was determined by spectrophotometry
for the TiO2 layers grown at different temperatures; the decrease of the growth temperature increased the bandgap, confirming the nanocrystalline nature of the TiO2 films.[i]
[i] K. Shalini, S. Chandrasekaran, S.A. Shivashankar, J. Cryst. Growth, 2005, Vol.284, Iss.3–4, p.388-395, « Growth of nanocrystalline TiO2 films by MOCVD using a novel precursor », doi.org/10.1016/j.jcrysgro.2005.06.053,www.sciencedirect.com/science/article/pii/S0022024805007876