Sr9La2(WO6)4 containing [WO6] octa-hedra

Rayko Simura; Tomoki Watanabe; Hisanori Yamane

doi:10.1107/S2056989022006648

Sr₉La₂(WO₆)₄ containing [WO₆] octa-hedra

Acta Crystallogr E Crystallogr Commun. 2022 Jul 5;78(Pt 8):766-769. doi: 10.1107/S2056989022006648. eCollection 2022 Aug 1.

Authors

Rayko Simura¹, Tomoki Watanabe¹, Hisanori Yamane¹

Affiliation

¹ Institute of Multidisciplinary Research for Advanced Materials, Tohoku, University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan.

Abstract

A polycrystalline sample of Sr₉La₂(WO₆)₄, nona-strontium dilanthanum tetra-kis-[orthotungstate(VI)], was prepared by heating a compacted powder mixture of SrCO₃, WO₃, and La₂O₃ with an Sr:La:W molar ratio of 9:2:4 at 1473 K. X-ray crystal structure analysis was performed for a Sr₉La₂(WO₆)₄ single-crystal grain grown by reheating the sample at 1673 K. Sr₉La₂(WO₆)₄ crystallizes with four formula units in the tetra-gonal space group I4₁/a and is isotypic with Sr₁₁(ReO₆)₄. Two W sites with site symmetries of are located at the center of isolated [WO₆] octa-hedra, and four mixed (Sr/La) sites are surrounded by eight to twelve O atoms of the [WO₆] octa-hedra. The structure of Sr₉La₂(WO₆)₄ can be described on the basis of the double-perovskite structure with [WO₆] and [(Sr/La)O _x ] polyhedra alternately placed, and a vacancy (□).

Keywords: crystal structure; double perovskite; tungstate.

Grants and funding

Funding for this research was provided by: JSPS KAKENHI (grant No. JP20K20363); the Cooperative Research of the Development Center for Advanced Materials, Institute for Materials Research, Tohoku University (grant No. 202112-CRKEQ-0208); the Tohoku University Center for Gender Equality Promotion Support Project.