Influence of magnetic viscosity on the first order reversal curves of antiferromagnetically coupled perpendicular recording media

Measurement of first order reversal curves (FORC) is emerging as a common characterization method to understand the exchange and magnetostatic interactions in magnetic films. In this paper, the FORC of the top and bottom layers of an antiferromagnetically coupled (AFC) perpendicular recording media is studied. The AFC media shows four peaks in the FORC contours, as against a single peak observed in the FORC of typical magnetic samples. Moreover, it is also pointed out that the FORC contours may be affected by time-dependent magnetization effects.