Identification of the place causing Barkhausen noise in yoke type MR heads

In yoke-type magnetoresistive (MR) heads, Barkhausen noise occurs in different regions depending on various applied fields. The place causing the noise can be specified by comparing the observed change of noise with the calculated field distribution in the head when an internal bias is superimposed on a uniform external field. Using a recording coil current instead of a uniform external field, noise from a bottom yoke or a substrate is clearly detected.<>