CURRENT EFFECTS IN MAGNETOSTRICTIVE PIEZOELECTRIC SENSORS

Some important improvements in magnetostrictive piezoelectric sensors have been obtained by applying an alternating current to the ferromagn etic amorphous ribbon. First, we present a way to minimize the hystere sis in these devices using a demagnetizing current through the magneti c sample. Second, the current, at a frequency half that of the longitu dinal piezoelectric resonance, is used to induce size changes in the h igh-magnetostriction amorphous ribbon, and these changes, which depend on the external magnetic held, can be read by the piezoelectric suppo rt. Then, with this configuration, it is not necessary to have a coil for the detection of a magnetic held.