Synthesis, structure and properties of layered Pr₂MoO₆-based oxymolybdates doped with Mg

Undoped and Mg-doped Pr₂MoO₆ oxymolybdate polycrystals and single crystals have been prepared by solid-state reactions and flux growth. The compounds have been characterized by powder X-ray diffraction, energy-dispersive spectroscopy, inductively coupled plasma mass spectrometry, scanning transmission electron microscopy, single crystal X-ray structure analysis, differential scanning calorimetry and thermogravimetry. The (MgO)_x(Pr₂O₃)_y(MoO₃)_z (x + y + z = 1) solid solution series has been shown to extend to x = 0.03. The structure of the Mg-doped Pr₂MoO₆ single crystals can be represented as superimposed lattices of the main matrix (Pr₂MoO₆) and lattices in which Mo atoms are partially replaced by Mg. The incorporation of Mg atoms into the structure of Pr₂MoO₆ results in the disordering of the praseodymium and oxygen lattices. Both the polycrystalline and single-crystal Mg-doped samples are hygroscopic.