Synthesis, crystal structure and ionic conduction pathways simulation of Ag2-2xNa2xMn2(MoO4)3 (x = 0.925)

Abstract

A new mixed molybdate Ag0.15Na1.85Mn2(MoO4)3 has been synthesized by a solid-state reaction and its crystal structure determined from single crystal X-ray diffraction data. It crystallizes in the triclinic system, space group P-1, with a = 7.0668 (7) Å, b = 8.7951 (8) Å, c = 10.7556 (9) Å, α = 113.214 (6)°, β = 102.295 (5)°, γ = 103.084 (3)° and isostructural to Ag2Mn2(MoO4)3 (Tsyrenova et al., 2004 [1]). The structure of Ag0.15Na1.85Mn2(MoO4)3 can be described as being composed of Mn2Mo2O14 double-chains that are interconnected by corner-sharing with MoO4 tetrahedra, leading to a three-dimensional framework with channels propagating in [100], [010] and [001] in which the monovalent cation are located. The structural model was validated by the bond valence sum (BVS) and charge distribution (CHARDI) methods. The bond-valence-sum-pathways (BVSP) and the bond-valence-site-energy (BVSE) analysis were extended to simulate the ionic conduction properties of monovalent cations in the anionic framework, correlate the crystallographic and electric properties and discuss the effect of partial substitution of silver in Ag2Mn2(MoO4)3 by sodium on ionic conduction.