X-ray study of deformation density and spontaneous polarization in ferroelectric NaNO2

• Published in: Acta crystallographica. Section B, Structural science Structural science, 2000-02, Vol.56 (1), p.11-16
• Main Authors: Gohda, T., Ichikawa, M., Gustafsson, T., Olovsson, I.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Crystal binding; cohesive energy; Crystalline state (including molecular motions in solids); deformation density; Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; ferroelectrics; Inorganic compounds; Niobates, titanates, tantalates, pzt ceramics, etc; Physics; Salts; spontaneous polarization; Structure of solids and liquids; crystallography; Structure of specific crystalline solids
• ISSN: 0108-7681; 1600-5740
• DOI: 10.1107/S010876819901054X

The deformation electron density of ferroelectric sodium nitrite has been determined from X‐ray diffraction data at 30 K, using Hirshfeld deformation functions. Owing to the strong correlation between odd terms of the deformation coefficients, constraints were imposed in the refinement. The net charges for Na, N and O atoms were estimated to be 0.27, 0.20 and −0.24 e, respectively. The calculated spontaneous polarization using these net charges and atomic dipole terms, 7.8 µC cm−2, is much closer to the recently measured value, 12 µC cm−2, as compared with the value calculated from the formal point charges (74 µC cm−2).