Synthesis and Characterization of Ilmenite-Type Cobalt Titanate Powder

Cobalt titanate (CoTiO3) powder was prepared by a modified sol‐gel method. The precursor solution could be prepared by cobalt acetate and titanium isopropoxide using various solvents either with or without HCl. After post‐heat treatment in air from 500 to 900 °C, CoTiO3 powder with increasing crystallinity was obtained. The fundamental properties of the powder were characterized by X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), and Brunauer‐Emmett‐Teller (BET) analysis. The effects of post‐heat treatment at different temperatures were discussed based on results of these analyses. The results showed that single‐phase CoTiO3 can be prepared by straightforward sol‐gel spin‐coating method followed by heat treatment at fairly low temperature of 550 °C. The dielectric constant of the CoTiO3 powder thus prepared was found to be 34.5 by C‐V analysis. High‐k material application is promising for the CoTiO3 powder thus prepared. The single‐phase CoTiO3 powder is successfully prepared at the relatively low temperature of 550°C by a modified sol‐gel spin‐coating method. XRD and XPS studies revealed that increasing the post‐heat treatment temperature leads to an increase in crystallinity and a decrease in the binding energies of Co 2p, Ti 2p, and O 1s electrons. The dielectric constant of annealed CoTiO3 annealed is 34.5. (Special issue dedicated to Professor H. H. Wei on the occasion of his 70th birthday and retirement)