An investigation of the archivability of metal particle tape

We studied the rate of degradation of the data storage capability of three commercial and two experimental metal particle (MP) tapes in an impinging jet geometry designed to eliminate irreproducibility in accelerated atmospheric testing. Both the bulk loss of saturation magnetization and a profile of the loss of magnetization through the media were measured. The most corrosion-resistant of the commercial tapes lost less than 5% of its magnetization from the top 25% of the media after 20 days of exposure to an intensified Battelle Class II environment. The experimental tapes lost even less. Thus at least one commercial MP tape exhibited substantial corrosion resistance under direct exposure to a strongly corrosion-accelerating environment. Furthermore, the loss of magnetization proceeded nearly uniformly throughout the media, which agreed with the conclusion that the particles were well-armored against corrosive species. The corrosion resistance of the best of the MP media listed above was no worse and perhaps even better than samples of chromium dioxide media that accompanied the MP coupons in every experiment