Effect of bias magnetic field on the magnetostrictive vibration of amorphous ribbons

Abstract

Electromagnetic waves generated from the magnetostrictive vibrations of amorphous ribbons under nonuniform bias fields were investigated. The sample ribbon 80 mm in length was placed on a plastic support board where both edges of the ribbon were free. In a uniform bias field generated by a Helmholtz coil, four resonance peaks of 27, 54, 81, and 107 kHz were detected. The nonuniform magnetic fields were generated by single-pole magnetic heads. Two single-pole magnetic heads with 3 mm spacing between the ribbon were moved along the ribbon. When the heads were located at 10 and 70 mm from an edge of the ribbon, the frequency of the detected response was 54 kHz, i.e., the detected response was the second resonance peak. The other resonance peaks (81, 107, and 129 kHz) could also be separated by adjusting the positions of the heads. Therefore, the electromagnetic response of the magnetostrictive vibrations of amorphous ribbons could be controlled by applying appropriate nonuniform bias magnetic fields. From the results, it is suggested that a magnetostrictive amorphous ribbon not only sends one bit data but also sends multiple bit data with the aid of bias magnetic fields.