摘要 |
<p>A self-biasing magnetostrictive element (10) for use in a magnetomechanical EAS marker is a strip of amorphous alloy material distributed throughout the bulk of the amorphous alloy strip. The crystalline particles (12) are magnetized to bias the amorphous alloy strip (14) to resonate in response to an interrogation signal. The crystalline particles (12) are formed by heat-treating the amorphous alloy strip (14) at a temperature above the Curie temperature of the amorphous alloy in the presence of a longitudinal magnetic field. The alloy strip (14) is then cross-field annealed at a temperature below the Curie temperature of the amorphous alloy to form a transverse anisotropy in the amorphous bulk of the alloy strip (14). A preferred alloy composition includes iron, cobalt, niobium, copper, boron and silicon.</p> |