Effect of F AF coupling strength on the magnetization process of F AF system

The effect of the exchange coupling strength J between NiFe and FeMn layers on the magnetization process in NiFe/FeMn structures was investigated. Sam ples with structures of NiFe/impurity (or Cu)/FeMn and NiFe/FeMn were prepa red and measured to determine their hysteresis loop shift H-p and coercivit y H-c. It is often assumed that H-p is proportional to J. However, our resu lts show that H-p dependence on J is not monotonic. A phenomenological mode l is proposed to explain the results. A better method for estimation of J i s also proposed. (C) 1999 Elsevier Science B.V. All rights reserved.