Ferroelectric crystals with periodic laminar domains

Abstract

Abstract This paper reviews our researches on the growth, the characterization and the physical properties of ferroelectric crystals with periodic laminar domains. The growth of LiNbO3 and LiTaO3 crystals with periodic laminar domains has been achieved in Czochralski growth system. The melt was doped with solutes such as yttrium, indium or chromium. Either eccentric rotations or applying electric current pulses with reversed polarities was used to induce the growth striations in the growing crystals. Two kinds of domain walls, the smooth vs. the rough have been found with electron microscopic observations. The determination of solute concentration variation along the growth axis shows that there are sharp minima and broad maxima which correspond to the smooth and the rough domain walls. The mechanism for the formation of periodic laminar domains has been discussed. Components of a 3rd rank tensor such as nonlinear optical or piezoelectric coefficient may change sign across a ferroelectric domain wall. For...