Single source heterobimetallic precursors for the deposition of Cu-Ti mixed metal oxide thin films

Heterobimetallic molecular precursors [Ti-4(dmae)(6)(mu-OH)(mu-O)(6)Cu-6(benzoate)(9)] (1) and [Ti-4(dmae)(6)(mu-OH)(mu-O)(6)Cu-6(2-methylbenzoate)(9)] (2) were prepared by the interaction of Ti(dmae)(4) [dmae = N,N-dimethylaminoethanolate] with Cu(benzoate)(2)center dot 2H(2)O for (1) and Cu(2-methylbenzoate)(2)center dot 2H(2)O for (2), respectively, in dry toluene, for selective deposition of Cu/Ti oxide thin films for possible technological applications. Both the complexes were characterized by melting point, elemental analysis, FT-IR, thermal analysis and single crystal X-ray analysis. Complex (1) crystallizes in the triclinic space group P-1 and complex (2) in the rhombohedral space group R-3. The TGA analysis proves that complexes (1) and (2) undergo facile thermal decomposition at 550 degrees C to form copper titanium mixed metal oxides. The SEM/EDX and XRD analyses suggest the formation of carbonaceous impurity free good quality thin films of crystalline mixtures of beta-Cu3TiO4 and TiO2 for both (1) and (2), with average grain sizes of 0.29 and 0.74 mu m, respectively. Formation of two different homogenously dispersed oxide phases is also supported by electrical impedance measurements.