RELATIONSHIP BETWEEN HIGH-DENSITY RECORDING PERFORMANCE AND PARTICLE COERCIVITY DISTRIBUTION

Most magnetic recording media are composed of magnetic crystalline particles having inherent coercivity originating from crystalline and shape anisotropies. The relationship between the statistical distribution of the particle's coercivity and the high density magnetic recording characteristics was investigated. In order to estimate a width of the Particle Coercivity Distribution (PCD) in a medium, we introduced a new method in which the PCD can be obtained from M-l-i major and minor curves. The PCD correlates strongly with the coercivlty squareness (S*) and the switching field distribution (SFD), and needs no compensating for the demagnetizing field even in perpendicular recording media. It was shown that a sharper PCD resulted in much better recording performance, particularly in perpendicular recording media.