Abstract
Dielectric and photorefractive dependence on 180° domain was investigated by employing the BaTiO3 single crystal. Dielectric constant depends on the volume ratio between antiparalell domains. When the antiparalell domains were equal in volume, ϵ c and ϵ a were 130 and 2600 respectively. In the single-domain state, ϵ cunclamped and ϵ cclamped were 141 and 65, ϵ aunclamped and ϵ aclamped were 4300 and 2000, respectively.