Cobalt boride (Co2B) particle synthesis by one-step carbothermic reduction

Abstract

In this study, crystalline Co2B powder production was carried out by a one-step carbothermal reduction method starting from cheap, easily accessible oxide-based materials. Firstly, to determine the carbothermic CoxB formation conditions, the decomposition temperatures of the raw materials were analysed by TG/DTA, and the temperature-varying Gibbs free energies of the expected reactions were calculated. Then, Co2B production was carried out at constant CoO/B2O3/C (3.22/1.5/1.3) weight ratios at temperature (1273-1473 K) and time (30-270 min). scanning electron microscopy (SEM), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM) were used to characterize the particles. XRD results showed that reaction temperature and time are the primary control on CoxB formation. Single-phase crystalline Co2B particles with crystallite sizes of 88 nm were successfully produced at 1473 K and 150 min. The permanent magnetization, saturation magnetization, and coercivity values of Co2B particles were defined as 16.58 Oe, 35.361 emu/g, 0.501 emu/g, respectively