| 摘要 |
PURPOSE:To obtain the ferrite magnet having both high coercive force and high magnetic flux density without reducing residual magnetic flux density by a method wherein a specific quantity of CoO is contained in the ferrite magnet of a fundamental composition together with one or two kinds of a specific quantity of CaO, SiO2, Cr2O3 or Al2O3. CONSTITUTION:CaO of 0.2-1.0 wt. %, SiO2 of 0.3-1.0 wt. %, one or two kinds of Cr2O3 and Al2O3 of 0.05-5.0 wt. %, and CoO of 0.05-1.5 wt. % are contained in the ferrite magnet having the fundamental composition of Fe2O3/ MO (M in the formula indicates Pb, Ba and Sr) of 5.0-6,2 in mol ratio. CaO and SiO2 are effective for control of sintering density and the size of crystal grains. Also, the addition of Cr2O3 and Al2O3 is especially effective for improvement in iHc. The CoO has a remarkable effect for improvement in iHc in the state wherein it is coexisted with CaO, SiO2, Cr2O3 and Al2O3. |
