| 摘要 |
PURPOSE:To improve the density and abrasion resistance of an oxide ferrite by adding specific amounts of Al2O3 and CaO to an oxide ferrite having a specific composition composed of ferric oxide, manganese oxide and zinc oxide. CONSTITUTION:The objective oxide magnetic material is produced by adding 0.01-0.3wt.% of Al2O3 and 0-0.2wt.% of CaO as subsidiary components to an oxide ferrite used as a main component and composed of 50-56mol% of ferric oxide, 20-40mol% of manganese oxide and 6-30mol% of zinc oxide. The magnetic material has high density and excellent abrasion resistance compared with conventional ferrite material. It has sufficiently good magnetic properties for the use as a head material. When the amounts of Al2O3 and CaO exceed the upper limit in the above composition, the magnetic permeability of the material abruptly decreases. |
