Synthesis, crystal structures, and properties of new acentric glaserite-related compounds Rb7Ag5–3Sc2+(XO4)9 (X = Mo, W)

Synthesis, crystal structures, and properties of new acentric glaserite-related compounds Rb7Ag5–3Sc2+(XO4)9 (X = Mo, W) Full article

Journal

Journal of Solid State Chemistry
ISSN: 0022-4596 , E-ISSN: 1095-726X

Output data

Year: 2022, Volume: 305, Article number : 122638, Pages count : 9 DOI: 10.1016/j.jssc.2021.122638

Tags

Rubidium; Silver; Scandium; Triple molybdate; Triple tungstate; Phase equilibria; Synthesis; Crystal structure; Ionic conductivity

Authors

Spiridonova Tatyana S. ¹ , Solodovnikov Sergey F. ² , Molokeev Maxim S. ^3,4 , Solodovnikova Zoya A. ² , Savina Aleksandra A. ^1,5 , Kadyrova Yulia M. ¹ , Sukhikh Aleksandr S. ² , Kovtunets Evgeniy V. ¹ , Khaikina Elena G. ¹

Affiliations

1	Baikal Institute of Nature Management, Siberian Branch, Russian Academy of Sciences, Sakh'yanova St. 6, Ulan-Ude, 670047, Buryat Republic, Russian Federation
2	Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Akad. Lavrentyev Ave. 3, Novosibirsk 630090, Russian Federation
3	Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Akademgorodok 50 bld.38, Krasnoyarsk, 660036, Russian Federation
4	Kemerovo State University, Krasnaya St., 6, Kemerovo, 650000, Russian Federation
5	Skolkovo Institute of Science and Technology, Moscow, 121205, Russian Federation

The subsolidus phase equilibria in the system Ag2MoO4–Rb2MoO4–Sc2(MoO4)3 were studied and two new triple molybdates, Rb9Ag3Sc2(MoO4)9 and Rb7Ag5Sc2(MoO4)9, were found. The structures of Rb7Ag5Sc2(MoO4)9 and isostructural Rb7Ag5Sc2(WO4)9 of the Cs7Na5Yb2(MoO4)9 type (the space group R32) were determined. The found composition of the triple tungstate crystal, Rb7Ag4.61Sc2.13(WO4)9, indicates a non-stoichiometric compound formula, Rb7Ag5–3xSc2+x(WO4)9. Both structures have one incompletely occupied Ag site, and structure Rb7Ag4.61Sc2.13(WO4)9 also contains two positions with mixed Ag and Sc. Both compounds contain ‘lanterns’ [M2(XO4)9] (M = (Sc, Ag), Sc; X = Mo, W), which are strengthened by three AgO2 dumbbells to give isolated building blocks [Ag3M2(XO4)9] forming two-story hexagonal layers resembling the structure of glaserite K3Na(SO4)2. Similar layers of [Ag3Sc2(WO4)9]9- building blocks were also found by us in the structure of Rb9–xAg3+xSc2(WO4)9, which is close to that of Rb9Ag3Sc2(MoO4)9. Similar layers of the [M2(TO4)9] units were also observed in Cs7Na5Yb2(MoO4)9 and Na13Sr2Ta2(PO4)9. The title compounds belong to the series of rhombohedral triple molybdates and tungstates with a = 9–10 Å and large c-periods (more than 20 Å), which have layered or open 3D framework structures. Like many compounds of this series, Rb7Ag5Sc2(XO4)9 (Х = W, Mo) at elevated temperatures have significant ionic conductivity reaching values 6.1⋅10-3 S cm-1 at 703 K (X = Mo) and 1.4⋅10-3 S cm-1 at 733 K (X = W) with Еа = 0.7 eV and 0.6 eV, respectively.

Spiridonova T.S. , Solodovnikov S.F. , Molokeev M.S. , Solodovnikova Z.A. , Savina A.A. , Kadyrova Y.M. , Sukhikh A.S. , Kovtunets E.V. , Khaikina E.G.
Synthesis, crystal structures, and properties of new acentric glaserite-related compounds Rb7Ag5–3Sc2+(XO4)9 (X = Mo, W)
Journal of Solid State Chemistry. 2022. V.305. 122638 :1-9. DOI: 10.1016/j.jssc.2021.122638 WOS OpenAlex

Submitted:	Aug 10, 2021
Accepted:	Oct 4, 2021
Published online:	Oct 14, 2021

Web of science:	WOS:000711213600003
OpenAlex:	W3206432063

DB	Citing
Web of science	6
OpenAlex	9