等方性並びに異方性Ca-La-Pb系フェライト磁石の磁気特性

概要

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The present experiment has been carried out to investigate the effect of PbO substitution on some properties of isotropic and anisotropic Ca-La system ferrite magnets. The composition of the compound were chosen according to the formula (CaO_<1-X>PbO_X・6Fe_2O_3)_<97>(La_2O_3)_3, where x was varied between 0 and 1.0. The raw materials used in this experiment were α-Fe_2O_3, CaCO_3, La_2O_3 and PbO powder. Mixed powder of the raw materials prepared by the wet-mixing method were semisintered at 900-1275℃ in dry O_2 gas for 1h. The resulting products were finely ground by the ball-milling crusher, compacted into cylindrical specimens in or without the magnetic field, and then sintered at 1175-1300℃ in dry O_2 gas for 0.5h. The experimental results summarized are as follows. The magnetic properties of (CaO_<1-X>PbO_X・6Fe_2O_3)_<97>(La_2O_3)_3 magnets were apparently improved by substitution of PbO for (CaO・6Fe_2O_3)_<97>(La_2O_3)_3 compound, and this effect of PbO might be due to the acceleration of the sintering velocity. Isotopic Ca-La-Pb system ferrite magnets semisintered at 1000℃, and anisotropic these magnets semisintered at 1200℃ were equivalent to ordinary Ba and Sr ferrites in their magnetic properties. Isotropic Ca-La-Pb system ferrite magnets which have the value of 8.0-12.5 kJ/m^3, and anisotropic magnets which have the value of 25.0-29.0 kJ/m^3 could be prepared by the conventional manufacturing technique.
明治大学の論文