| 摘要 |
PURPOSE:To obtain uniaxial anisotropic powder finer than ever and to obtain an excellent recording medium with use of the powder by incorporating elements selected respectively from three groups in addition to Fe and O into powder of hexagonal ferrite having mean particle diameter and coercive force respectively in the specified range. CONSTITUTION:Magnetic powder of hexagonal ferrite contg. >=1 kind selected from a group of Ba, Sr, Ca, and Pb, >=1 kind selected from a group of Ti, Co, Ni, N, Cu, Zn, In, Ge, Nb, Zr, and Sb, and >=1 kind selected from a group of Ce, Pr, Nd, Pm, Sm, and Eu along with Fe and O, having 0.01-0.3mu mean particle diameter, and having 200-2,000 Oe coercive force is manufactured. The magnetic powder of a magnetoplumbite type shown by the formula Ba1-xMXFe10.8-xTi0.6Co0.6+xO19, where M is Pr and Nd, (x) is 0-0.3, is preferably used. A magnetic paint obtained by dispersing the magnetic powder in a binder is coated on a supporting body, oriented in a vertical magnetic field, and then dried to obtain a recording medium having high reproduction output and excellent electromagnetic transducing characteristic. |
