Structure and antiferroelectric properties of cesium niobate, Cs2Nb4O11

Abstract

The compound cesium niobate, Cs2Nb4O11, is an antiferroelectric, as demonstrated by double hysteresis loops in the electric field versus polarization plot. The crystal structure refinement by X-ray diffraction at both 100 and 297 K shows it to have a centrosymmetric structure in point group mmm and orthorhombic space group Pima, which is consistent with its antiferroelectric behavior. The 100-K structure data is reported herein. The lattice is comprised of mobium-centered tetrahedra and octahedra connected through shared vertices and edges; cesium atoms occupy channels afforded by the three-dimensional polyhedral network. Antiferroelectricity is produced by antiparallel displacements of niobium atoms along the e-axis at the phase transition temperature of 165 degrees C. The critical field for onset of ferroelectric behavior in a single-crystal sample is 9.5 kV/cm at room temperature. (C) 2007 Elsevier Inc. All rights reserved.