Structure of the low-temperature phase of Rb3D(SeO4)2 by single-crystal neutron diffraction
2004 (English)In: Journal of Physics and Solids, no 65, 1095-1102 p.Article in journal (Refereed) Published
Crystal structure of Rb3D(SeO4)2 has been investigated at 25 K (below the transition temperature Tc = 95.4 K) by single-crystal neutron diffraction. Accompanying the transition, the SeC04 groups, which are all equivalent in the phase above the transition (space group A2/a), split into eight nonequivalent groups in a superlattice (a X 2b X 2c, space group A2) in the low-temperature phase. Based on the D atom positions obtained, each of the SeO4 groups was identified to be in the state closer to a HSeO4- ion or to a SeO4²- ion and the dipole arrangement of SeO4-D-SeO4 dimer was revealed. This dipole arrangement has 'ferri' structure along the polar b-axis, but 'antiferro' structure in the plane perpendicular to the b-axis. These results are consistent with the characteristics found in the earlier dielectric measurements.
Place, publisher, year, edition, pages
2004. no 65, 1095-1102 p.
Inorganic compounds, Crystal structure, Phase transitions, Ferroelectricity
IdentifiersURN: urn:nbn:se:uu:diva-66786OAI: oai:DiVA.org:uu-66786DiVA: diva2:94697