Magnetoacustic markers based on magnetic microwire, and method of obtaining the same

摘要

It concerns an activatable / deactivatable magnetomechanical marker, based on magnetic microwires, in which participates a non-bistable, magnetoelastic, soft magnetic microwire (1) with induced transversal magnetic anisotropy and with magnetoelastic resonance frequency of 58 kHz, and a second hard magnetic microwire (2), thereby achieving a substantial reduction in the size of the marker.
The procedure for obtaining the same consists firstly in obtaining a soft magnetic microwire with non-bistable magnetic behaviour, which undergoes a heat treatment in the presence of transversal magnetic field sufficient to saturate the sample at a temperature below that of crystallization of the amorphous alloy, cutting said magnetic wire to the appropriate length so that its magnetoelastic resonance coincides with that of the detecting unit, and finally obtaining a hard magnetic microwire (2) which together with the soft microwire are mounted on the mechanical support (3) of the marker.