Synthesis, sintering, electrical properties, and sodium migration pathways of new lyonsite Na2Co2(MoO4)3

A new double molybdate Na2Co2(MoO4)3 was synthesized via solid-state reaction and characterized by single-crystal X-ray diffraction (XRD). This compound is a new member of the lyonsite structure type. It crystallized in the orthorhombic system, space group Pnma with cell parameters a = 5.272(2) Å, b = 10.816(3) Å, and c = 18.064(3) Å. The structure can be described as a three-dimensional framework with hexagonal tunnels in which the Na+ cations lie. The obtained structural model is supported by charge distribution analysis and bond valence sum validation tools.