Synthesis of nanosized rubidium ferrite by thermolysis of ferricarboxylate precursors and combustion method

Nanosized pure rubidium ferrites have been successfully prepared by thermal decomposition of rubidium hexa(carboxylato)ferrate(III) precursors, Rb3[Fe(L)6]·xH2O (L = formate, acetate, propionate, butyrate), in flowing air atmosphere from ambient temperature to 1000 °C. Various physico-chemical techniques i.e. simultaneous TG–DTG–DTA, XRD, Transmission Electron Microscope (TEM), IR and Mössbauer spectroscopy etc. have been employed to characterize the intermediates and end products. After dehydration, the anhydrous precursors undergo exothermic decomposition to yield various intermediates i.e. rubidium carbonate/acetate/propionate/butyrate and α-Fe2O3. A subsequent decomposition of these intermediates, followed by solid state reaction, lead to the formation of nanosized rubidium ferrite (RbFeO2). The same nano-ferrite has also been prepared by the combustion method at a comparatively lower temperature and in less time than that of the conventional ceramic method (>1200 °C).

► The precursor and solution combustion method result in the formation of ferrite particles with average size of 30–80 nm.
► Mossbauer studies show super-paramagnetic phase in the final ferrite product.
► XRD pattern confirms the formation of cubic ferrite with α-LiFeO2 type geometry.