Barkhausen noise in thin-film recording heads

Barkhausen noise in thin-film heads was studied by exciting the heads with an external magnetic field and with a head-coil-generated field. Observed pulses show an exponential growth and decay, resulting in a second-order wall energy versus displacement model. Analytical expressions are given for the observed pulse shapes. Most pulses are essentially associated with unstable regions around attractive interaction sites where a wall in equilibrium cannot exist. A method is presented which can detect in which pole piece (P/sub 1/ or P/sub 2/) a wall jump occurs. It also differentiates wall jumps located close to the pole faces from those occurring deeper in the yoke.<
>