FORMATION AND ANNIHILATION OF EDGE WALLS IN THIN-FILM PERMALLOY STRIPS

Comparison between magneto-resistance measurements and Kerr observatio ns confirm that the formation and annihilation of edge walls in thin P ermalloy strips, formed during rotation of an external field, is respo nsible for hysteresis in angular positioning sensors. The annihilation field required to avoid this unwanted behavior strongly depends on th e strip cross section. Micromagnetic calculations assuming rectangular cross section yield higher absolute field values than those observed, but help to clarify the sensor behavior as field and material paramet ers are varied.