Dr. Rene van de Veerdonk

Seagate Research

"Magnetic Characterization of Perpendicular Recording Media"

We have used Polar MOKE measurements and micromagnetic calculations based on Monte-Carlo techniques to characterize the magnetic properties of perpendicular recording media.  In the presentation, I will go over the various measurements that are routinely performed and the information that can be gained from them. Using a combination of different measurements and independent input on the structure of the samples, many of the microscopic parameters can be determined with reasonable accuracy.

One measurement of special interest that will be introduced in more detail is the characterization of Switching Field Distributions using a collection of recoil loops, with particular focus on the differentiation between the effects of the demagnetizing field and the intrinsic switching field distribution in samples with perpendicular anisotropy. This technique can be extended to the characterization of energy barrier distributions.