THE INFLUENCE OF DOMAIN ACTIVITIES ON MR HEAD PERFORMANCE

The relation of signal distortion of MR heads to the domain structure and the domain activities was studied in this paper. Several kinds of MR elements were fabricated and a measurement system was set up to mea sure magnetoresistivity, A large drop near the peak of the output wave form was found for some MR elements. And the magnetic structure of th e MR element was investigated by the ''Bitter pattern.'' It was seen t hat there existed multidomain in the part of the lead without gold coa ting. Furthermore, it was also found that the multidomain existed in t he junction of leads and the MR element, and the new domain looked lik e a hook. The appearance of this hook-shaped multidomain has not been reported up to now in literature. The design of the MR element was mod ified to eliminate the drop in the output wave form and the drop was r educed substantially. Our study shows that suitable geometric dimensio ns and structures of leads are also very important to high performance of MR head in head design in addition to select the optimum biasing c onditions. (C) 1996 American Institute of Physics.