Magnetic Augment in the Nitrogen Substituted Bismuth Ferrite

The nitrogen substituted bismuth ferrite polycrystal sample BiFeO2.1N0.9 has been successfully synthesized using sol-gel method. Its structural and magnetic properties are investigated. The formation of Fe4+ due to charge compensation is found in BiFeO2.1N0.9 from X-ray photoelectron spectra. The crystal structure of BiFeO3 is barely affected by N doping while the magnetic property is well improved. We propose that it is the coexistence of different superexchanges (Fe-N-Fe and Fe-O-Fe) that breaks the magnetic cancellation effect of the spin spiral, hence increasing the macroscopic magnetization.