ZnFe2O4 thin films from a single source precursor by aerosol assisted chemical vapour deposition

A single source heterobimetallic complex [Fe2(acac)4(dmaeH)2][ZnCl4] (1) (acac = 2,4-pentanedionate, dmaeH = N,N-dimethylaminoethanol), was synthesized in high yield. The complex was analyzed by melting point, Fourier transfer infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The structure of the cation was established by single crystal X-ray analysis on a derivative, [Fe2(acac)4(dmaeH)2][ZnCl3(THF)]2·THF (1a) (THF = tetrahydrofuran). TGA analysis showed that complex (1) undergoes facile thermal decomposition at 450 °C to give ZnFe2O4 residue. In-house designed aerosol assisted chemical vapour deposition equipment was used to deposit thin films of ZnFe2O4 on fluorine doped SnO2 coated conducting glass substrate at 450 °C. X-ray diffraction analysis proved the formation of crystalline ZnFe2O4 phase and scanning electron microscopy revealed the film morphology with well defined crystalline particles evenly distributed in the range 150–200 nm. The indirect and direct bandgap energies of the thin films were estimated to be 1.76 and 2.10 eV, respectively.