New triple molybdate Rb2AgIn(MoO4)3: synthesis, framework crystal structure and ion-transport behaviour

Tatyana S. Spiridonova, Sergey F. Solodovnikov, Aleksandra A. Savina, Yulia M. Kadyrova, Zoya A. Solodovnikova, Vasiliy N. Yudin, Sergey Yu Stefanovich, Elena G. Khaikina

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

A new triple molybdate, Rb2Ag1+3xIn1–x(MoO4)3 (0 ≤ x ≤ 0.02), was found in the course of a study of the system Rb2MoO4–Ag2MoO4–In2(MoO4)3 and was synthesized as both powders and single crystals by solid-state reactions and spontaneous crystallization from melts. The structure of Rb2Ag1+3xIn1–x(MoO4)3 (x ≈ 0.004) is of a new type crystallizing in the centrosymmetric space group Rc [a = 10.3982 (9), c = 38.858 (4) Å, Z = 12 and R = 0.0225] and contains (In,Ag)O6 octahedra and distorted Ag1O6 trigonal prisms linked by common faces to form [Ag(In,Ag)O9] dimers connected to each other via MoO4 tetrahedra into an open three-dimensional (3D) framework. Between two adjacent [Ag(In,Ag)O9] dimers along the c axis, an extra Ag2O6 trigonal prism with about 1% occupancy was found. The Ag1O6 and Ag2O6 prisms are located at levels of z ≈ 1/12, 1/4, 5/12, 7/12, 3/4 and 11/12, and can facilitate two-dimensional ionic conductivity. The 12-coordinate Rb atoms are in the framework cavities. The structure of Rb2AgIn(MoO4)3 is a member of the series of rhombohedral 3D framework molybdate structure types with a ≈ 9–10 Å and long c axes, which contain rods of face-shared filled and empty coordination polyhedra around threefold axes. Electrical conductivity of ceramics is measured by impedance spectroscopy. Rb2AgIn(MoO4)3 undergoes a `blurred' first-order phase transition at 535 K with increasing electrical conductivity up to 1.1 × 10−2 S cm−1 at 720 K. Thus, the compound may be of interest for developing new materials with high ionic conductivity at elevated temperatures.

Original languageEnglish
Pages (from-to)1603-1609
Number of pages7
JournalActa Crystallographica Section C: Structural Chemistry
Volume74
Issue number12
DOIs
Publication statusPublished - 1 Dec 2018

Keywords

  • crystal structure
  • indium
  • ionic conductivity
  • powder X-ray diffraction
  • rubidium
  • silver
  • triple molybdate
  • PHASES
  • PACKINGS
  • SERIES
  • CR
  • SC
  • R=AL
  • SOLID-SOLUTION
  • DIFFRACTION
  • MG
  • FE

Fingerprint Dive into the research topics of 'New triple molybdate Rb<sub>2</sub>AgIn(MoO<sub>4</sub>)<sub>3</sub>: synthesis, framework crystal structure and ion-transport behaviour'. Together they form a unique fingerprint.

Cite this