High-Density Recording Characteristics of Obliquely Oriented Particulate Magnetic Tapes by Removal of Disoriented Surface Layer
In order to achieve high recording densities, wide bandwidth and high output, a magnetic tape should have a high Bs, perpendicular orientation, a smooth surface, good head contact, and a small longitudinal component. By using a "LIPS" orienting process which produces media with a longitudinally oriented inside layer and a perpendicular oriented surface layer, we have fabricated obliquely oriented magnetic films based on acicular metal particles; of these, tape oriented at 45° had the widest-bandwidth characteristics. But a significant improvement in output was not obtained because of the existence of disoriented particles in the surface layer, resulting from calendering treatment. We tried to remove this surface layer using polishing sheets. An obliquely oriented (45°) tape exhibited an improvement in short-wavelength output (by 10 dB at 0.3 ¿m) after the thickness of the disoriented layer was reduced by 0.12 ¿m.
A Particulate Medium Oriented Longitudinally Inside and Perpendicularly at Surface
This report takes another look at the VAST (Vertical magnetic orientation-AC demagnetization-Smoothing period-sequential Train) technique used to fabricate double-layer particulate media oriented longitudinally inside and perpendicularly at the surface from CrO2 particles and nitrocellulose with a urethane binder. Infrared irradiation was performed to evaporate the solvent instead of natural evaporation to improve the viscosity of the surface perpendicular oriented layer, and to ensure a controlled thin, uniform thickness surface layer.
Perpendicular magnetic recording--Its basics and potential for the future
In this tutorial paper, perpendicular and longitudinal magnetic recording are compared in terms of their fundamental magnetization transition sharpness and magnetostatic energy per bit. The superiority of perpendicular recording to longitudinal recording at high densites is demonstrated. Perpendicular recording with ring-shaped heads is also discussed. Performance and structural features are compared for several different head configurations.