Abstract
Many reports have been issued about ferrite permanent magnets as well as their magnetism. limiting in Ba and Sr system ferrites.
The present experiment has been carried out to investigate the optimum condition for preparing isotropic Ca ferrite magnets having the best magnetic and physical properties. Compositions were chosen according to the fomula (CaO⋅nFe2O3)100-x(La2O3)x and (CaO1-ySrOy⋅6Fe2O3)97 (La2O3)3, where x was varied between 0 and 4.0, n was varied between 5.5 and 6.25, and y was varied between 0 and 1.0.
The results are as follows; 1) The best magnetic properties of (CaO⋅nFe2O3)100-x(La2O3)x compounds were obtained in n=6 and x=3.2) To obtain magnets having (BH)max more than 1.0 MG⋅e, semi-sintering at the temperature above 1200°C is required. 3) Curie temperature of (CaO⋅6Fe2O3)100-x(La2O3)x compounds increases with the increase of x value. 4) The magnetic properties of (CaO1-ySrOy⋅6Fe2O3)97(La2O3)3 magnet are improved by substitution of SrO for CaO.
