SIZE-DEPENDENT MAGNETIC-PROPERTIES OF ZINC FERRITE FINE PARTICLES

We investigate the particle size dependence of magnetic properties of ZnFe2O4 fine particles. The fine particles with different particle siz es were obtained by heating the coprecipitated powder. The magnetizati on slowly increases with decreasing the particle size, and drastically in the particles with diameter < 30 nm. The size dependent magnetizat ion shows maximum around similar to 8 nmin diameter. The Curie tempera ture also increases with decreasing the particle size. Such changes in the magnetization and Curie temperature can be explained in terms of the distribution of Fe3+ ions dependent on the particle size.