Magnetics of small magnetoresistive sensors (invited)

In the application of magnetoresistive sensors to magnetic recording two basic magnetic issues must be addressed: namely, the suppression of domain effects and the linearization of the magnetoresistive (MR) response. In this paper, we examine past results of the Barkhausen noise problem in small MR sensors, as well as methods for their suppression. Furthermore, we shall also discuss various transverse bias schemes: their principles of operation, their advantages and limitations in terms of bias sensitivities, bias uniformity, as well as their impacts on the linear and track resolution of the MR sensor.