Reducibility and magnetic properties of nanosized ZnO substituted Fe₂O₃/TiO₂system

Abstract

Pure Fe 2 O 3 and TiO 2 powder were mixed in molar ratio and fired in a muffle furnace at 1200uC for 4 h. The Fe 2 TiO 5 compound formed was doped by replacing TiO 2 with calculated amounts of ZnO (ZnO fractions x50?2, 0?4, 0?6, 0?8 and 1). The synthesised samples were characterised with X-ray diffraction (XRD) and their magnetic properties were measured using a vibrating sample magnetometer. Fe 2 TiO 5 , 2FeZnTiO 4 , Fe 2 ZnTi 3 O 10 , ZnTiO 3 and ZnFe 2 O 4 phases were detected with very low magnetic properties corresponding to dilute magnetic semiconductors. Reduction tests in hydrogen at 500uC showed the reducibility of the undoped compound to be very low and to increase gradually with increasing Zn content in the ferrite phase. The reduction process caused a pronounced change in the magnetic properties.