Design of amorphous magnetic materials for high frequency sensors based upon permalloy characteristics

Fabrication of harmonic sensor for the rapidly expanding technology of electronic article surveillance (EAS) is addressed. The focus is on the magnetic characteristics relevant to sensors in EAS. The principal characteristic of materials which make them suitable as harmonic tags is highly non-linear B–H characteristics stemming from near zero magnetic anisotropies. Specifically, field annealing as well as magnetic domain engineering is described for high response signals.