Abstract
We have studied the N-dependent switching behavior of composite magnets, comprised of a hard CoPtCr-SiO 2 (CPCS) film and a laminated soft [Pt/CPCS] N multilayer. First order reversal curve magnetometry provides evidence of interfacial domain wall (iDW) assisted reversal for N ≥5. The magnetic depth profiles determined from polarized neutron reflectometry (PNR) explicitly demonstrate that the composite magnets are more rigidly coupled for N 3 than for N 7, and suggest that for N 7 reversal occurs via formation of iDW. By fitting the PNR profile into the energy surface calculations, we can further deduce the vertical coupling strength in the laminated soft layer. © 2013 AIP Publishing LLC.