| 摘要 |
A tag or marker is disclosed which comprises a substrate; an 'active' magnetic material which is a soft magnetic material having a high magnetic permeability and a low coercive force; and a deactivating material which is a hard or semi-hard magnetic material having a moderate or high coercive force and a moderate magnetic permeability, whereby the deactivating material, when subjected to a sufficiently high magnetising force, is able to clamp the magnetic properties of the 'active' material so as to deactivate the 'active' material. The tag or marker is characterised in that at least one of said 'active' material and said deactivating material is formed by an electrodeposition process. In another aspect, the deactivating material is formed from a steel containing 0.15 % carbon, 16-18 % chromium, and 6-8 % nickel, the balance being iron. |
