DIPOLAR FIELD FLUCTUATION EFFECTS ON PHONON ECHOES IN PIEZOELECTRIC POWDER

One-shot phonon echo in piezoelectric powder was studied in order to simplify the experimental condition and clarify the basic mechanism on this phenomenon. One-shot phonon echo is observed by the application of the single sequence of the incident electric pulses. The one-shot two-pulse echo was observed to have relaxation characteristics with the function of exp(-α τ2). The dynamic relaxation is clarified to originate in the effect of the local field fluctuation in a large number of the oscillating piezoelectric particles