Synthesis, Structures, and Properties of Layered Quaternary Chalcogenides of the General Formula AlnEQ₄ (A = K, Rb; Ln = Ce, Pr, Eu; E = Si, Ge; Q = S, Se)

Abstract

Four related quaternary compounds containing rare-earth metals have been synthesized employing the molten flux method and metathesis. The reactions of Eu and Rb2S5 with Si and Ge in evacuated fused silica ampoules at 725 °C for 150 h yielded RbEuSiS4 (I) and RbEuGeS4 (II), respectively. On the other hand, a reaction between CeCl3 and K4Ge4Se10 at 650 °C for 148 h has yielded KCeGeSe4 (III) and KPrSiSe4(IV) was obtained by the reaction of elemental Pr, Si and Se in KCl flux at 850 °C for 168 h. Crystal data for these compounds are as follows: I, orthorhombic, space group P212121 (#19), α = 6.392(1), b = 6.634(2), c = 17.001(3) Å, α = ß = γ = 90°, Z = 4; II, monoclinic, space group P21/m (#11), a = 6.498(2), b = 6.689(3), c = 8.964(3) Å, ß = 108.647(6)°, Z = 2; III, monoclinic, space group P21 (#4), a = 6.852(2), b = 7.025(2), c = 9.017(3) Å, ß = 108.116(2)°, Z = 2; IV, monoclinic, space group P21 (#4), a = 6.736(2), b = 6.943(2), c = 8.990(1) Å, ß = 108.262(2)°, Z = 2. The crystal structures of I-IV contain two-dimensional corrugated anionic layers of the general formula, [LnEQ4]- (Ln = Ce, Pr, Eu; E = Si, Ge and Q = S; Se) alternately piled upon layers of alkali cations. In addition to structural elucidation, Raman and UV-visible spectroscopy, and magnetic measurements for compound III (KCeGeSe4) are also discussed.

Department(s)

Chemistry

Keywords and Phrases

Chalcogenides (Quartenary); Rare-earth Elements

International Standard Serial Number (ISSN)

0044-2313

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, All rights reserved.

Publication Date

02 Nov 2006

Link to Full Text

Share

 
COinS