Semi-hard magnetic elements and method of making same
AssigneeSensormatic Electronics Corporation
InventorsNen-Chin Liu, Robert C. O'Handley, Wing Ho, Richard Copeland
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Abstract
A semi-hard magnetic element is formed of an amorphous soft iron-metalloid material containing at least 50 atomic percent iron and at least a part of the bulk of which has been crystallized to give the overall element semi-hard magnetic properties.
Claims42
A magnetic element comprising an amorphous magnetically soft iron-metalloid material at least a part of the bulk of which has been crystallized to give the overall magnetic element semi-hard magnetic properties, said amorphous magnetically soft iron-metalloid material containing at least 50 atomic percent iron.
A method of making a magnetic element comprising:
- providing a magnetic element comprised of an amorphous magnetically soft iron-metalloid material containing at least 50 atomic percent iron;
- and
- annealing the amorphous material for a time and at a temperature sufficient to crystallize the bulk of the material to give the overall magnetic element semi-hard magnetic properties.
A tag for use in an EAS system comprising:
- a signal generating first magnetic element having an activated state in which the signal generating first magnetic element is able to interact with an applied magnetic field and a deactivated state in which the signal generating first magnetic element is disabled from interacting with said applied magnetic field;
- a second magnetic element disposed adjacent said signal generating first magnetic element for placing said signal generating first magnetic element in said activated and deactived states, said second magnetic element comprising an amorphous magnetically soft iron-metalloid material at least a part of the bulk of which has been crystallized to give the overall second magnetic element semi-hard magnetic properties, said amorphous magnetically soft iron-metalloid material containing at least 50 atomic percent iron.
An electronic article surveillance system for detecting the presence of a tag in an interrogation zone comprising:
- a tag comprising:
- a signal generating first magnetic element having an activated state in which the signal generating first magnetic element is able to interact with a magnetic field and a deactivated state in which the signal generating first magnetic element is disabled from interacting with said magnetic field;
- and a second magnetic element disposed adjacent said signal generating first magnetic element for placing said signal generating first magnetic element in said activated and deactivated states, said second magnetic element comprising an amorphous magnetically soft iron-metalloid material at least a part of the bulk of which has been crystallized to give the overall second magnetic element semi-hard magnetic properties, said amorphous magnetically soft iron-metalloid material containing at least 50 atomic percent iron;
- means for transmitting said magnetic field into the interrogation zone;
- and
- means for receiving a signal resulting from said signal generating first magnetic element of said tag interacting with said magnetic field.
A method for detecting the presence of a tag in an interrogation zone comprising:
- providing a tag comprising:
- a signal generating first magnetic element having an activated state in which the signal generating first magnetic element is able to interact with a magnetic field and a deactivated state in which the signal generating first magnetic element is disabled from interacting with said magnetic field;
- and a second magnetic element disposed adjacent said signal generating first magnetic element for placing said signal generating first magnetic element in said activated and deactivated states, said second magnetic element comprising an amorphous magnetically soft iron-metalloid material at least a part of the bulk of which has been crystallized to give the overall second magnetic element semi-hard magnetic properties, said amorphous magnetically soft iron-metalloid material containing at least 50 atomic percent iron;
- transmitting said magnetic field into the interrogation zone;
- and
- receiving a signal resulting from said signal generating first magnetic element of said tag interacting with said magnetic field.
Dependencies are inferred from the claim text.