Phase formation in Li2MoO4-K2MoO4-MMoO4 (M = Ca, Pb, Ba) systems and the crystal structure of α-KLiMoO4

• Published in: Russian journal of inorganic chemistry 2011-09, Vol.56 (9), p.1443-1452
• Main Authors: Gudkova, I. A., Solodovnikova, Z. A., Solodovnikov, S. F., Zolotova, E. S., Kurat’eva, N. V.
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Physicohemical Analysis of Inorganic Systems
• ISSN: 0036-0236; 1531-8613
• DOI: 10.1134/S0036023611090075

Solid-phase interactions in Li 2 MoO 4 -K 2 MoO 4 -MMoO 4 (M = Ca, Pb, Ba) systems were studied, and the subsolidus regions of these systems were triangulated. The lead and barium systems were studied in a more detailed way to discover that, along KLiMoO 4 -K 2 M(MoO 4 ) 2 (M = Pb, Ba), KLiMoO 4 -PbMoO 4 , and Li 2 MoO 4 -K 2 Ba(MoO 4 ) 2 quasi-binary sections, there are homogeneity regions reaching 6–11 mol % based on K 2 M(MoO 4 ) 2 and lead molybdate. Triple molybdates are formed in none of the systems, which is verified by experiments on spontaneous crystallization from solution in melt. Crystallization experiments yielded crystals of potassium dimolybdate and simple and double molybdates from the boundary systems. The crystal structure was solved for a hexagonal KLiMoO 4 phase: (Na,K){ZnPO4}, a = 18.8838(7) Å, c = 8.9911(6)Å, Z = 24, space group P 6 3 , R = 0.065. The structure comprises a three-dimensional tridymite framework built by an alternation of corner-sharing LiO 4 - and MoO 4 tetrahedra wherein voids are occupied by potassium cations.