| 摘要 |
PURPOSE:To produce high output in a wide zone by forming a magnetic layer contg. magnetic powder with uniaxial anisotropy and magnetic powder with isotropic anisotropy by which the powder is not oriented but is magnetized in any direction and having specified squareness in each of the vertical and horizontal directions and a specified orientation ratio. CONSTITUTION:Magnetic powder with uniaxial anisotropy such as gamma-Fe2O3 or Co powder is mixed with magnetic powder with isotropic anisotropy such as spheroidal or needlelike powder of iron oxide contg. solubilized Co. The former powder is easily oriented by applying a magnetic field, and by applying the magnetic field in the horizontal direction, the powder is oriented in the horizontal direction to produce high output in a low frequency zone. The latter powder is hardly oriented even by applying a magnetic field in any direction, but the powder is easily magnetized in any direction, so it contributes to the increase of output especially in a high frequency zone. A magnetic layer contg. said mixture and having 500-2,000 Oe coercive force, >=0.3 squareness in the vertical direction, >=0.6 squareness in the horizontal direction and 0.3-<1.0 squareness ratio, that is, orientation ratio is formed. Thus, high output is produced in both of low and high frequency zones. |
