| 摘要 |
PURPOSE:To prevent large reduction in initial magnetic permeability in a high- frequency range by adding a specific amount of cobalt oxide to a ferrite in a composition range consisting essentially of Fe, Mn and Zn and having high saturation magnetization. CONSTITUTION:This single crystal ferrite comprises 65-75mol% Fe2O3, 20-30mol% MnO, 5-15mol% ZnO and 0.01-1mol% CoO. The ferrite may be further blended with 0. 01-0.1mol% MgO and 0.05-0.1mol% hafnium oxide. In a single crystal ferrite consisting essentially of Fe, Mn and Zn, it is considered that initial magnetic permeability is extremely reduced since magnetic anisotropic constant K in a composition range having high saturation magnetization is negative and absolute value of the constant K is considerably larger than 0. By adding CoO having positive constant K, single crystal ferrite having high initial magnetic permeability can be developed and high saturation magnetization attained. Exceeding of the upper limit of CoO extremely reduces the initial magnetic permeability. |
