Electroluminescence study of polarization changes in lead magnoniobate crystals in pulsed electric fields

Electroluminescence is used to study changes in the polarization of crystals of a model ferroelectric relaxor, lead magnoniobate (PMN), in pulsed electric fields. The amplitude of the electoluminescence pulses produced during polarization and depolarization of PMN crystals is found to depend on the duration of the applied electric field pulses if this duration is shorter than the most probable time for polarization buildup. These data provide evidence of rapid changes in the polarization through realignment of the domain and heterophase structure at temperatures above the temperature for destruction of the induced macrodomain ferroelectric phase and evidence of an “excited” polarization state for short-lived pulses whose decay is accompanied by an enhancement in the amplitude of the depolarizing luminescence pulse and by a reduction in the time delay of its emission following the end of the field pulse. Fiz. Tverd. Tela (St. Petersburg) 39, 341–343 (February 1997)