Influence of proton-exchange conditions on ferroelectric domain inversion caused in LiTaO/sub 3/ crystals

Proton exchange followed by heat treatment of LiTaO/sub 3/ crystals causes domain inversion at the negative surface. The dependence of the ferroelectric inversion layer thickness on the proton-exchange time and temperature is experimentally investigated. The results show that there exists a threshold in proton-exchange time and temperature for forming the inversion layer, and that the inversion layer thickness can be approximately expressed by a unique function of the proton-exchanged layer thickness.