Temperature dependence of long-term magnetization stability for data storage tapes prepared from ultrafine particles

Time (t) dependence of the change in relative magnetization (ΔMrela) for a period of 1000 h was investigated for advanced data storage metal particulate (MP) tape and Ba-ferrite (BF) sheets prepared from ultrafine articles at 295 to 338 K. Time dependence of ΔMrela at 295 K in all samples obeyed a logarithmic law for 1000 h. ΔMrela/log t at all temperatures for BF sheet was much larger than that of MP tape because of lower anisotropy field component. Relative permanent magnetization loss due to the oxidation for MP tape at 295 K was negligibly, however it increased as temperature increased.