Magnetic properties and heat capacity of CoTiO3 nanopowders prepared by stearic acid gel method

Pure cobalt titanate nanopowders were successfully prepared in wet-chemistry synthesis method, using cobalt acetate and tetra-n-butyl titanate as Co and Ti sources and stearic acid as complexing reagent. The gel was calcined at different temperatures in air ranging from 500 degrees C to 650 degrees C. Results of thermal analysis are given; including both differential thermal gravimetry (DTG) and thermogravimetric. X-ray diffraction was used to characterise the crystallisation process, the particle size and morphology of the calcined powders. The results indicated that cobalt nanopowders with a particle size of about 35 nm could be obtained after calcinations of the dried gel at 600 degrees C for 2 h. In the temperature range between 80 degrees C and 500 degrees C, the empirical equation (CP (JK-1 mol-1) = -136.311 + 0.141 T - 3.551 x 107/T2) for the CP of CoTiO3 was determined from differential scanning calorimetry. The synthesised CoTiO3 indicate a superparamagnetic behaviour, as evidenced by using vibrating sample magnetometer at room temperature.