Ferromagnetic Resonance Investigations of Exchange Biased NiFe/IrMn/NiFe Trilayer Structures
Trilayer thin-film magnetic structures NiFe/IrMn/NiFe obtained by DC magnetron sputtering in the presence of a constant magnetic field 420 Oe were investigated by ferromagnetic resonance (FMR) technique. The dependences of the exchange bias, misalignment angle between the uniaxial and unidirectional anisotropies, and the FMR linewidth on the thickness of the antiferromagnetic IrMn layer in the range from 2 to 50 nm are compared for samples with hard Ni40Fe60 and soft Ni75Fe25 ferromagnetic layers of the same 10 nm thickness. Using the data of other authors and our previous data for bilayer structures, possible reasons of the observed dependences are discussed.