MICROMAGNETIC STUDIES OF ANTIFERROMAGNETISM AND RESISTANCE-FIELD CURVES IN GIANT MAGNETORESISTIVE CO AL/NIFE/

Magnetic properties and magnetoresistance of a Co/Al/NiFe giant-magnet oresistance (GMR) spin valve are analyzed by a new micromagnetic simul ation model for the strongly interacting soft magnetic materials, The coercivity is less than 10 Oe in an isolated Co or NiFe film, However, in the Co/Al/NiFe GMR structure with a 80 Angstrom interlayer spacing , the coercivity of the Permalloy film increases to 208 Oe; and the re mnant magnetization in the Co film even has an opposite sign with that in the NiFe film, which means the two magnetic films coupled anti-fer romagnetically in a zero external magnetic field, The looped resistanc e-magnetic field (R-H) curve is obtained, The noise during the switchi ng process can be decreased and the linearity of the R-H curve can be improved by an orientation distribution of anisotropy fields for the G MR sample.