Abstract
A novel sol-gel autocombustion process was used to synthesize ultrafine powders of nickel ferrite. This powder was prepared from metal nitrates and citric acid. The combustion process is an oxidation-reduction reaction in which the NO 3 − ion is the oxidant and the carboxyl group is the reductant. The results revealed that the nitrate-citrate gels exhibit a self-propagating behavior after ignition in air at room temperature. The ratio of metal nitrates to citric acid and different values of pH in the starting solution also affect the combustion process. The thermal decomposition and the phase evolution were investigated by DTA/TG and XRD techniques, respectively. By using this novel autocombustion method, an NiFe2O4 ferrite powder with crystallite sizes of 20–40 nm was obtained.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have