Cobalt titanate-cobalt oxide composite thin films deposited from heterobimetallic precursor

摘要

A single molecular heterobimetallic complex, [Co2Ti(μ3-O)(TFA)6{THF)3] (1) [TFA = trifluoroacetate, THF = tetrahydrofuran], was synthesized, structurally and spectroscopically characterized and implemented as a single-source precursor for the preparation of CoTiO3-CoO composite thin films by aerosol-assisted chemical vapour deposition (AACVD). The precursor complex was prepared by interaction of Co(OAc)2.4H2O [OAc = (CH3COO )] with Ti(iso-propoxide)4 in the presence of trifluoroacetic acid in THF, and was analysed by melting point, CHN, FT-IR, single-crystal X-ray diffraction and thermogravimetric analysis. The precursor complex thermally decomposed at 480 C to give a residual mass corresponding to a CoTiO3-CoO composite material. Good-quality crystalline CoTiO3-CoO composite thin films deposited at 500 C by AACVD and characterized through powder X-ray diffraction and scanning electron microscopy/energy-dispersive X-ray spectroscopy show that the crystallites have a rose-flower-like morphology with an average petal size in the range of 2-6 μm.