Head saturation effects in perpendicular and longitudinal recording

In this study we have investigated the effect of saturation of a narrow gap ring-type-head on the amplitudes and gradients of the horizontal and vertical head field components for both longitudinal and perpendicular magnetic recording systems. The head field calculations were performed by finite element analysis simulating the geometry of a narrow gap ferrite ring head. We found a remarkable difference between the behavior of the horizontal gradient of the longitudinal field component ( ) and vertical head field component ( ) as the head core is driven into saturation. From computational results of head field and experimental results of the signal output versus write current response, we found that a) we have to consider recording demagnetization and its dependency on in "quasi-perpendicular" recording systems, i.e., ring-type head with Co-Cr media, as well as longitudinal recording systems, and b) we have to choose the high Hc medium in the range where the head can achieve saturation recording to reduce the influence of record demagnetization and the dependence of signal output on write current.