| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic recording medium, the magnetic recording medium having a security characteristic by a method for using the magnetic recording medium and this use method. SOLUTION: This magnetic recording medium has a magnetic layer consisting of magnetic powder mainly composed of MnBi and at least one kind of the magnetic powder selected from oxide magnetic powder, metallic magnetic powder, alloy magnetic powder and compd. magnetic powder. Regenerative magnetic signals are previously recorded in this magnetic layer. When the signals are once rewritten, the subsequent rewriting is difficult. If the magnetic layer is once written by cooling the medium to a low temp. to a degaussing state, then recording the signals followed by cooling the medium again to a low tamp., the subsequent rewriting is difficult according to this use method. |
