FLUX OSCILLATIONS GENERATED BY VIBRATION OF IRON AT 22 KHZ

An EMF was observed with a coil surrounding specimens of iron vibratin g in longitudinal resonance at 22.5 kHz, with no applied field other t han the earth's. For amplitudes within the range of validity of the Ra yleigh law, the signal varies as the 3/2 power of the strain amplitude but is a good sinusoid in time. This form is very reproducible, but t he amplitude depends on the magnetic state. At higher amplitudes, in t he super-Rayleigh region, the nature of the signal changes greatly in both amplitude dependence and frequency content, and also produces cha nges in the signals at lower amplitude, changes that depend on the tim e at high amplitudes. Recognition of these two regions, and of their f eatures, does much to reconcile apparent conflicts between investigato rs. The 3/2 power law suggests that the signal is driven by the mechan ism of mechanical loss in the Rayleigh region.