FORMATION OF HEXAGONAL FERRITE PARTICLES FROM THE DISORDERED FE2O3-BAO-B-2-O-3 SYSTEM

It was shown that by high energy milling and subsequent annealing of t he disordered powders from the BaO - Fe2O3 - B2O3 system crystalline p articles of hexagonal barium ferrite are produced, whose formation com mences slightly above 700 and is practically completed at about 800 de grees C. Both the X-ray diffraction and Mossbauer spectroscopy confirm ed that the ensuing phase possesses the magnetoplumbite structure and its relative amount increases with the annealing temperature and/or ti me at the expense of the ferric oxide. These data are in reasonably go od quantitative agreement viith the results of the measurements of the magnetic moment of the particle systems.