リラクサー強誘電体

—バルク，薄膜，人工格子—

抄録

Relaxor type ferroelectrics are treasure boxes both for basic physics and practical applications. Among them, Ba(Zr, Ti)O₃ is one of the candidate materials for elucidating the mechanism of relaxor phenomena. It has homo-valent B-site ions of Zr⁴⁺ and Ti⁴⁺. Therefore, there is no driving force to push the ions into ordered structure. On the other hand, it has a possibility of co-existence of multi phases (so-called pinching effect). In case of the bulk state, we have found that the relaxor behavior is strongly affected by the annealing conditions. To make clear the intrinsic parameter for the relaxor, we have demonstrated the artificial control of the positioning of the B-site ions by the superlattice technique. The stacking periodicity and the compositional combination of BaTiO₃ and BaZrO₃ are changed systematically with this method and the sign of the relaxor is detected.