Abstract
We have investigated the delay time properties of magnetoelastic wave (ME wave) in amorphous Fe-B films prepared by rf-cosputtering. Films were deposited as thick as 10 μm onto aluminium foils of about 20 μm in thickness, which enable us to observe the bulk mode of ME wave. We also made similar experiment for liquid quenched Fe80B20 ribbons for comparison. The fractional change of the sound velocity |C−Cs|/Cs by the application of a static bias field Hb is about 4% for the film (atf = 100 kHz), which is about one third smaller than that of the ribbons. This is considered that the films used here are still magnetically hard (Hc = 1 Oe for the films, while 0.1 Oe for the ribbons) mainly due to strong constraint from aluminium substrate.
Analysis was made on the delay time properties of ME wave in terms of one-dimensional elastic bar taking the micro-eddy current damping into consideration, by which the bias field and the frequency deoendences of the sound velocity can fairly well be explained.
