Effects of additionals on the magnetic properties were observed in PbO-Fe_2O_3-MO system, varying the sintering conditions and the value of Fe_2O_3/PbO. Substituting PbO or Fe_2O_3 for SnO, ZnO, CdO, MgO, NiO, CuO, CoO, Cr_2O_3, B_2O_3, GeO_2, SiO_2 and ZrO_2, etc., it was found that Cr_2O_3, B_2O_3, GeO_2 and SiO_2 are effective. Best results were obtained in these systems mixed at Fe_2O_3/PbO=4?5 by mol and sintered at 950°?1100℃. Magnetic properties of the improved PbO system oxide magnets were comparable to those of the BaO or SrO system.
Science reports of the Research Institutes, Tohoku University. Ser. A, Physics, chemistry and metallurgy 8 540-546, 1956