HISTORY DEPENDENT DOMAIN-STRUCTURES IN GIANT-MAGNETORESISTIVE MULTILAYERS

Resistance noise measurements of several types reveal the field histor y dependence of domain structure in sputtered Co/Cu multilayers. We fi nd many smaller domains as the field is decreased from saturation towa rds zero, but as the field changes sign and is increased in the opposi te direction we observe a smaller number of larger domains. Cycling th e field without changing its sign preserves the smaller domains, stron gly reducing the Barkhausen noise, Discrete fluctuations in resistance due to individual domains yield domain size estimates. (C) 1995 Ameri can Institute of Physics.