Heterometallic (Nickel, Titanium)-Containing Dimethylglyoximates as Precursors for Nickel Titanate Coating

Heterometallic (nickel, titanium) dimethylglyoximate (II) with a nickel : titanium ratio of 1 was synthesized from nickel(I) dimethylglyoximate and titanium tetrachloride TiCl 4 in chloroform. Resulting complex II was characterized by X-ray diffraction analysis (XRD), electron paramagnetic resonance (EPR), IR spectroscopy, and elemental analysis. It was shown that the synthesized complex II is a solvate. On the basis of the studies carried out, an assumption was made about the possible structure of complex II. It was found that the thermal decomposition of complex II begins at 44°C. A constant mass of the decomposition product is observed in the temperature range of 590–850 °C. According to X-ray diffraction analysis (XRD) of the thermolysis product, the main crystalline phase is nickel titanate NiTiO 3 ; there are also up to 5 wt % of nickel oxide NiO and titanium oxide TiO 2 , as well as carbon. Complex II was used to obtain a nickel titanate coating of a corundum substrate. A solution of complex II, dissolved in dimethyl sulfoxide C 2 H 6 OS, was applied to a previously prepared surface of aluminum oxide (corundum) by immersing the substrate in the solution, after which it was fired at 850°C, the organic part (dimethylglyoxime) (III) pyrolyzed, and a coating was formed. According to X-ray diffraction data, the resulting coating is characterized by a perovskite structure and belongs to nickel titanate. An insignificant admixture of the rutile phase was detected, the content of which did not exceed 5 wt %.