| 摘要 |
PURPOSE:To obtain magnetic powder for high-density vertical oxidation recording by mixing B2O3 as a glass forming substance with starting materials including basic and substitute components of ferrite in a specified ratio, melting the mixture, rapidly cooling the melt, and heat treating the resulting amorphous body. CONSTITUTION:In the triangular component diagram having AO (A is one or more among Ba, Sr, Ca and Pb), B2O3 and Fe2O3 contg. a substitute component as vertexes, a composition region is formed by connecting 4 points (a) B2O3=44, AO=46, Fe2O3=10mol%, (b) B2O3=40, AO=50, Fe2O3=10mol%, (c) B2O3=10, AO=40, Fe2O3=50mol% and (d) B2O3=20, AO=30, Fe2O3=50mol%. A mixture in the region excepting the points (a), (d) and the line connecting the 2 points is melted and rapidly cooled. The resulting amorphous body is heated to 650-850 deg.C to deposit magnetoplumbite type ferrite powder, which is then treated with acid. |
