Annealing study of the erasability of high energy tapes

The effects of high temperature long-term aging on the erasability of various high coercivity tape media were investigated. The results showed that Co-γ-Fe₂O₃ media, depending on how they were prepared, could become increasingly harder to erase, or stay virtually unchanged in their erasability after prolonged aging. For CrO₂ media, experiments indicated that aging the media at high temperatures could cause severe erosion, which badly degraded the media magnetic properties and recording performance, as well as altered the media erasure characteristics. Much less severe corrosion was observed for metal particle media. Aging the metal evaporated media at high temperatures caused their coercivity to increase, by as much as 30%, which was also reflected in the media erasure characteristics. Of all the media studied, Ba-ferrite was found to be the most stable against the annealing process