Domain effects in the thin film head

An analysis is presented showing that delays in the response of thin film heads can lead to distortions in the shape of isolated pulses including decreases in the peak amplitude, increases in the isolated pulse half width, and, in extreme, the disappearance of the negative amplitude trailing edge of the pulse characteristic of the thin film head. Examples of thin film heads have been found exhibiting isolated pulse forms corresponding to variable delay times after near saturation of the head in writing. These examples suggest that variable domain structures in the head are associated with these delays. One specific model for domain wall motion in the head is considered in detail showing a relationship between the equations of motion of domain walls and the delay times associated with the portions of the head blocked by closure domains.