Abstract
Ultrafine ilmenite CoTiO3 powders were prepared with sol–gel method. The effects of preheating treatment on the morphology of powders were studied using X-ray diffraction (XRD) and SEM. The powders were characterised as an antiferromagnetic material in crystallography and as a ceramic pigment in chromaticity. The XRD analysis revealed that single phase ilmenite CoTiO3 powders were obtained by calcining at 700°C for 3 h with and without preheating and were of vivid blue green colour and of average particle sizes of 42˙5, 41˙9 and 45˙2 nm for non-preheated and preheated powders at 300 and 400°C respectively. The calculated c/a ratio increased from 2˙7440 to 2˙7455 and 2˙7474 with increasing preheating temperature. The SEM analysis indicated that the powders were uniform in size and the size and morphology of particles changed with preheating schedules. The powders were of luminance factor of Y=19˙77 and chromaticity coordinate value of x=0˙2765 and y0˙3600.