Recording characteristics of MIG heads

The recording characteristics of two different types of metal-in-gap (MIG) heads for rigid disks have been studied. In one the surface facing the recording medium is trapezoidal, while in the other it is straight. Both heads show excellent recording performance, especially for high-H_c media, compared to non-MIG heads. D₅₀ was 30 KFCI with an H_c=1200 Oe disk. The trapezoid type MIG head has 30% higher output voltage than the parallel type, but has a frightening field at the gap, so the effective track width is 2~3 μm wider than the optical track width. The parallel type has less fringing field