Media noise in periodic multilayered magnetic films with perpendicular anisotropy

Periodic, finely multilayered thin-film magnetic structures (≤200 Å) with high in-plane coercivity suitable for longitudinal recording investigations have been fabricated. CoPt20/Pd and CoPt12Cr17/Pd periodic multilayers can exhibit a perpendicular orientation, originating from surface anisotropy effects, with a magnitude depending on the thickness of the component layers. The perpendicular orientation influences the transition noise, but for the particular systems studied, the results suggest that for a given value of coercivity squareness, ≲0.8, the greatest improvements in media noise performance can be achieved through reduced exchange in films with a well-defined, in-plane orientation.