Preparation of small particles of SrFe12O19with high coercivity by hydrolysis of metal-organic complexes

Small particles (50-60nm) of Sr ferrite (SrFe12O19) have been synthesized by the hydrolysis method of metal-organic complexes such as metal acetylacetonates or metal ethoxides and subsequent heat-treatments of the precipitates, and their magnetic properties have been studied. X-ray, Mössbauer and electron-microscope studies have been conducted to examine the mechanism of the formation. A coercive force of 6700 Oe, one of the highest values reported so far for isotropic SrFe12O19samples and close to the theoretical limit, has been obtained. Some of their magnetic properties have been discussed in terms of magnetism of small particles.