Magnetic recording medium having light and heavy magnetisation axes - uses first type of magnetic particles and second type of uniformly aligned, strongly anisotropic particles

摘要

Magnetic recording medium with first type of magnetic particles has second type of uniformly aligned uniaxially strongly anisotropic particles (5). One axis is of light magnetization and a number of axes is of heavy magnetization. The axis of the light magnetization has an intrinsic coercive force of less than 1900 Oersted. Initially the second particle population is magnetized with a field of at least 2500 Oersted in the light magnetization axis. The residual magnetic moment of the particle population is at least 40 per cent. higher than the initial residual magnetic moment after an alternating field for erasing has been introduced in one of the magnetization axes.