[10p-M116-1~22] 9.1 Dielectrics, ferroelectrics

△ [10p-M116-7] Fabrication and Evaluation of Dielectric Property of K(Ta, Nb)Si₂O₇ Single Crystals

〇(M1C)Miho Onuma¹, Hiroaki Takeda¹, Takaaki Tsurumi¹, Takuya Hoshina¹ (1.Tokyo Tech.)

Keywords:ferroelectric, single crystal, silicate compound

KNbSi₂O₇(KNS)is a novel ferroelectric material having a structure in which SiO₄ tetrahedron enters between perovskite structures. First-principles calculation has revealed that ferroelectricity induced by the displacement of Nb⁵⁺ in the direction of [001] in the NbO₆ octahedron. Moreover, it has been confirmed experimentally that KNS single crystal exhibits ferroelectricity in the c-axis direction. In this study, we fabricated single crystals of KTa_xNb_1-xSi₂O₇ (KTNS, x=0-0.3) in which a part of Nb ions was substituted with Ta, and evaluated the crystal structure and the dielectric and ferroelectric properties.