DLC-based wear protection on magnetic storage media

The high storage capacity of flexible storage media requires the use of very thin write-and-read heads in order to function successfully. Such sensitive heads would be destroyed relatively quickly by the abrasive effect of tapes or floppy disks. Therefore, wear protective coatings were investigated in terms of their ability to reduce the wear damage caused to recording heads by tapes or floppy disks. The best-known example of the application of wear protective coatings on data storage media is in the production of hard disks. The following project was devised in order to examine whether the very thin wear protective coatings, employed successfully in hard disk production, could also be applied as a protective coating in the production of tapes and floppy disks in which the magnetic pigment used incorporates metal particles (MP). The experimental wear protective coating layer was applied to a digital-Betacam-SP tape. Adhesion failure at the interface between the magnetic head and the tape surface resulted, eventually, in the failure of the tape. Floppy disks, with a storage capacity of more than 100 MB, were also coated and tested. The coating caused a reduction in the disk's voltage level at the reading head, and other magnetic values recorded confirmed the quality reducing influence of the DLC layer on the floppy disk. The results obtained from long-term coated floppy disk tests were comparable to the results obtained in similar tests on uncoated floppy disks. The experiments proved that a DLC protective coating could be developed which would make a further improvement in the storage media systems possible, using high quality tapes and floppy disks. The major obstacle remains the elimination of the tape's adhesion problems caused by the lubricant component of the storage medium. (C) 2002 Elsevier Science B.V. All rights reserved.