| 摘要 |
PROBLEM TO BE SOLVED: To improve frequency characteristic in a high frequency band by baking hexagonal system Z type barium ferrite having composition wherein a part of Co is substituted by Fe, while at least equal permeability and radio wave absorbing performance are held in the air and an atmosphere wherein oxygen partial pressure is controlled. SOLUTION: Hexagonal system Z type barium ferrite has composition (Ba3 Co2-xFexFe24O41) wherein Co is substituted by required amount of Fe, and the amount of substitution of Fe is set to be 0<x<=1.2. The barium ferrite has characteristic wherein a real number part μr' of complex permeability μr is at least 3.5 at 1 GHz, and the peak of an imaginary number part μr" exceeds 0.5 GHz, and, under a suitable condition, has characteristic wherein the real number part μr' of complex permeability μr is at least 4 at 1 GHz, and the peak of the imaginary number part μr" exceeds 1 GHz. By the composition wherein Co is substituted by a required amount of Fe in order to generate stably a Z type single phase, and by the baking in at atmosphere wherein a specified oxygen partial pressure is selected in accordance with the composition, the hexagonal system Z type barium ferrite is obtained. |
