Hysteretic ferromagnetic resonance as a probe for coercivity, exchange bias, and loop asymmetry

Ferromagnetic resonance studies of in-plane angular variations of exchange bias and coercivity, using increasing and decreasing field sweeps, was presented. The measurements were carried out a frequency ω₀/2π=9.57 GHz using standard reflection-type spectrometer with a transverse electric cavity in an electromagnet. Experiments were carried out at room temperature on a F/AF Co/MnPt bilayer. It was found that the angular dependence of exchange bias and coercivity was in agreement with micromagnetic models in which the interfacial energy was approximately equal to the domain-wall energy in the antiferromagnet.