Structural Characterization of Materials for Magnetic Recording Heads and Disks

Results: For the head material, both exchange and chemical order develop with increasing thickness and the data show a correlation between these quantities. For the disk, data showed that this medium has a low level of fcc defects in the hcp Co-alloy which contributes to the high coercivity and thermal stability. We also found that the media has a high degree of preferred orientation, which results from the choice of seed layers and deposition conditions and results in high coercive squareness for good overwrite. In addition, there is no evidence of misoriented (c-axis) grains, which contribute to the high signal-to-noise ratio. In the materials for perpendicular recording, our data show that there is significantly more fcc Co-alloy than in comparable longitudinal media (ca < 30% compared with < 10%).