Attenuation of Magnetoelastic Waves in Amorphous Wires, and Its Applications

An improved technique was developed for measuring the attenuation constants of magnetoelastic waves in amorphous wires under an arbitrary magnetic field. Measured attenuation constants in an asquenched, a wire-drawn, an annealed, and a drawn and then annealed Fe-Si-B wire were determined as a function of the magnetic field applied to the sample wires. An extremely large value of the attenuation constant was observed in the annealed wire under no magnetic field. The value decreased rapidly when a magnetic field was applied to the wire. We also showed that the dependence of the attenuation constant on the magnetic field can be used to control the amplitude of the magnetoelastic waves.