Wall velocities, switching times, and the stabilization mechanism of 180° domains in congruent LiTaO3 crystals

Abstract

A systematic study of the kinetics of 180° domains as a function of external electric field is presented for Z-cut LiTaO3 single crystal wafers at room temperature using transient current measurements combined with nondestructive and real-time imaging of 180° domains by light microscopy. The switching time, wall velocity, and nucleation rate follow an exponential behavior with the applied field. A model is proposed which shows that the nucleation and sideways growth of domains play approximately equal parts in determining the switching time. A domain stabilization process occurs on the time scale of a few seconds even at electric fields where the switching time is milliseconds or less. We show that this stabilization process has a strong correlation to the internal fields in the crystal.