Magnetic medium capable of supporting both longitudinal and

Abstract

Acicular barium ferrite (BaFe) particles with magnetic easy axes perpendicular to particle length are utilized as the magnetic particles in the recording medium of the invention. The BaFe particles are coated to lie 'side by side', onto the medium's substrate with the particles' lengths lying in the plane he medium and transverse to the direction of medium motion during recording. The optimum particle orientation for support of both perpendicular and longitudinal components is where the easy axes of the particles are randomly oriented in an X-Y plane wherein the X axis Ks along the direction of media motion, and the Y axis is perpendicular to the recording layer. To effect this random orientation, the just coated particles are subjected to a rotating magnetic field whose rotating vector lies in the X-Y plane. As the magnetic layer is transported through the field past the rotating vector, the lengths of the particles align parallel to the Z axis and the easy axes of the particles align with the changing rotating field causing them to assume random directions in the X-Y plane. A rotating magnetic field may be generated by scanning down a pre-magnetized magnetic layer consisting of alternating polarity magnetic segments. If the media substrate coated with the still liquid dispersion of the BaFe particles is passed over such a pre-magnetized surface, each point of the dispersion will experience a rotating magnetic field and the desired random orientation will be obtained. The rotating field may also be obtained by means of a rotating magnet.