Recording Characteristics of BaM Thin Films

Evaluations of recording density using ring heads with relatively wide apertures on thin films of different Δθ₅₀ used for disk media (2 inch ø), and evaluations of the thermal stability of BaM thin films are reported. The possibility of obtaining a high recording density thin film with small Δθ₅₀ was clearly established. Changes in residual magnetization with respect to temperature variation were measured, revealing that when the film was left to stand for 15 h at 250°C approximately 10 percent thermal demagnetization occurred, and the film was almost completely demagnetized at 375°C.