Rapid synthesis of DyFeO3 nanopowders by auto-combustion of carboxylate-based gels

EDTA and citric acid as two typical chelating reagents with multi-carboxyl groups were used to prepare DyFeO3 nanopowders, respectively. The experimental results show that all of the carboxylate-based gels exhibited auto-propagating combustion behaviors. The XRD results indicate that DyFeO3 single phase can be formed directly with CA/MN (citric acid to metal nitrate mole ratio) = 1 when the calcination temperature was above 700 °C. The specimen with EA/MN (EDTA to metal nitrate mole ratio) = 1 had the minimum crystallite size of 33 nm. The SEM images show that the as-burnt powders prepared with EDTA had more excellent dispersibility feature and clearer grain boundaries than that of citric acid. The magnetic measurement results show that DyFeO3 nanopowders displayed antiferromagnetism characteristics at low temperatures due to the strong exchange interaction between Fe sublattice. As the ambient temperature increased, there was a transition from antiferromagnetism to paramagnetism in DyFeO3 nanopowders.