Crystal structure and ferroelectricity of cesium dihydrogen phosphate CsH2PO4

Abstract

Structural and dielectric studies have been performed on CsH2PO4 for scrutinizing the validity of the previously reported structure. It is found that the symmetry in the paraelectric state is not orthorhombic as previously assumed but monoclinic with the space group of C. The net configuration of hydrogen bond and the sequence of Cs and P are found to differ substantially from those of KH2PO4. Structural evidences combined with dielectric measurements indicate that the ferroelectricity of CsH2PO4 takes place through different atomic structure from that of KH2PO4 type ferroelectrics. L'etude structurale et dielectrique de CsH2PO4 a ete effectuee en vue de scruter la structure anterieurement rapportee. Nous avons trouve que la symetrie a la phase paraelectrique n'est pas orthorhombique comme prealablement connue mais monoclinique au groupe spatial C. La conformation de la liaison hydrogenee et la sequence de Cs et P different solidement de celles de KH2PO4. Ces faits structural combines avec les mesures dielectrique indiquent que la ferroelectricite de CsH2PO4 a lieu sous la structure atomique differente de celle des ferroelectriques au type de KH2PO4.