Soft-hard magnetic composite wires obtained by a modified current annealing technique

A current annealing procedure is proposed. Heat sinks were positioned along the sample, while annealing with current, inducing tailored temperature profile along its axis. Fe77.5Si7.5B15 amorphous wires were current annealed with this technique so that, magnetically soft and hard local regions develop. As a measure of this magnetic composite character, the coercivity profile was verified after annealing. Results are explained in terms of different power losses along the sample. Some possible applications as security labels of the annealed material are discussed.