Polarization Echoes and Long-Time Storage in Piezoelectric Powders

Abstract
Two- and three-pulse polarization echoes are detected in powders of mechanically resonant particles of piezoelectric materials. Under some conditions the decay time of the three-pulse echo can be of order one day or longer. A model for the echo formation and long decay time based upon the torque exerted on an oscillating dipole by an applied rf field is described.