Effect of secondary gaps in near-saturated metal-in-gap video heads

Secondary gaps between the ferrite bulk and the Sendust (AlFeSi alloy) shim mag occur in metal-in-gap (MIG) heads, Finite-element models are used to e xplore the effect that these gaps have on the read/write characteristics of single- and double-sided MIG heads. The presence of a secondary gap is sho wn to cause an additional peak in the writing field and oscillations in the magnitude of the response during replay. The field and response of a doubl e-sided MIG head is affected more than those of the corresponding single-si ded MIG head.