Canted anisotropy magnetoelastic resonance material as sensors for electronic article surveillance system

A self-biasing magnetostrictive element for a magnetomechanical Electronic Article Surveillance (EAS) marker is fabricated by annealing a ribbon of ferromagnetic amorphous material (Co_47.4Fe_31.6Si₂Bi₁₉) in a presence of magnetic field applied in a transverse direction relative to the ribbon’s longitudinal axis, and then annealing in a presence of magnetic field applied in the direction of the longitudinal axis. The two-step annealed ribbon exhibits remanent magnetization along the longitudinal axis and has plural magnetic domains situated along the longitudinal axis. The magnetic orientation of each domain is canted by ± 03B8; < 90° from the ribbon axis with the direction of canting alternating from domain to domain. To obtain such a canted anisotropy, theoretical background for the calculation of the field strength (H) and canted angle (θ) is described.