Performance and Stability of Soft Magnetic Elements for Electronic Article Surveillance

A simple figure of merit is proposed to compare the performance of soft magnetic elements for electronic article surveillance (EAS) applications. Annealing experiments were carried out to quantify the evolution of soft magnetic properties of amorphous-metal and Permalloy ribbons used in the library EAS industry. By fitting the kinetics of coercivity change to a simple model based on a uniformly distributed range of activation energies, the room-temperature kinetics of the amorphous elements is predicted