Research on Ferrite Magnet Materials

摘要

These experiments were canned out to investigate the effect of addition of various rare-earth oxides on the magnetic and physical properties of anisotropic or isotropic M-type (M = Ca, Sr, Pb, Ba) ferrites, and to mike clear the effect of the use of a new manufacturing method and the additives on the properties of anisotropic W-type(W = Sr, Ba, Pb) ferrites.In M-type ferrites, it was found the rare-earth oxide addition to these compounds (stoichiometric composition) was very useful in stabilizing the magnetoplumbite structure, and that these compound had excellent properties as a permanent magnet.In M~(2+)Zn_2-W-type ferrites, a new valuable manufacturing method which is characterized by the addition of M~(2+)O(PbO, SrO, BaO) after semisintering treatment without atmosphere control was established. It was found that this process was very useful in stabilizing the W-type hexagonal structure, and in improving the magnetic properties of these compounds. It cleared that the effective additives for the W-type ferrites are CaO, SiO_2, Na_2O, La_2O_3, MgO, Al_2O_3.