Hydrothermally Synthesized Spherocobaltite Nano-Particles

Abstract

Spherocobaltite, CoCO3, or cobalt carbonate is a mineral of calcite group. It finds applications in high-performance Li-ion batteries, as an animal feed trace elements, and also used as a precursors to synthesize cobalt oxide. In this study, spherocobaltite nano-particles are synthesized by hydrothermal method using cobalt sulphate solution and ammonium carbonate solution in the ratio of 1:3.The mixture was then transferred into a 100 ml Teflon-lined autoclave and heated at 140 °C for 4 h. The final sample is recovered by centrifugation redispersion cycle. The hexagonal crystal structure is confirmed by powder XRD, and the average crystallite size is determined by Scherrer’s formula and Williamson-Hall method, which is found to be within 14 nm. The presences of Carbon, Oxygen and Cobalt were confirmed by EDAX analysis. The TEM image suggests spherical morphology of the nano-particles. The FT-IR spectrum confirms the presence of functional groups such as O-H and C-O. The TGA curve suggests that the material starts dehydrating first and then decomposes in to cobalt oxide at 390o C temperature. The impedance and dielectric studies are carried out within 20 Hz to 2 MHz range at room temperature. The complex impedance and modulus plots are drawn and exhibiting the grain effect only. The VSM data taken at room temperature and low temperatures from 20 K to 300 K suggests a paramagnetic nature of the sample.