| 摘要 |
PURPOSE:To obtain a blue type magnetic powder exhibiting blue color by itself and sufficiently magnetizable by sintering a specified blue spinel and a magnetic oxide and specifying their molar ratio. CONSTITUTION:The blue spinel (BS) is represented by the composition formula: (MgO)a(CoO)b (Al2O3)c(Cr2O3)d, satisfying the following expressions among a, b, c, and d: 0<=a<=0.99, 0.5<=c<=4.0, a+b=1, and 0.25<=(a+b)/(c+d)<=2.0. The magnetic oxide (MO) is represented by the composition formula: (MeO)x(ZnO)y(Fe2O3)z, where M is Fe, Mn, Ni, Co, Cu, or Mg, and x, y, and z satisfy the following expressions; 0.4<=x<=1.0, 0.9<=z<=1.0, and x+y=1. The spinel BS and the oxide (MO) are sintered in such a molar ratio as 0.5<=BS/MO<=4.0, thus permitting the obtained blue type magnetic powder to exhibit blue color by itself and to be sufficiently magnetizable. |
