Seek durability for CoCrTa perpendicular flexible disks

The seek durability of CoCrTa perpendicular flexible disks was studied using a conventional 3.5-in double-sided flexible disk drive. The seek durability strongly depends on the CoCrTa film preparation conditions. The durability is increased by adding a Si underlayer for a CoCrTa film. Disk media yield pressures were evaluated with a scratch test using a sapphire needle. It is shown that high media yield pressure leads to a high seek durability. Ta addition to CoCr film increases the media yield pressure. The number of seek operations achieved was 200×10⁴, using the following disk construction: protective layer/CoCrTa film/Si underlayer/base film