Crystal structure of defect scheelite-type Nd_2/3[WO₄].

Area of Science:

• Solid-state chemistry
• Inorganic synthesis
• Crystallography

Background:

• Neodymium tungstates are of interest for their potential applications.
• Previous attempts to synthesize fluoride derivatives of neodymium tungstate were unsuccessful.
• Exploration of novel oxide structures is crucial for materials science.

Purpose of the Study:

• To report the unexpected synthesis and characterization of Neodymium(III) ortho-oxidotungstate(VI).
• To determine the crystal structure of the synthesized compound.
• To investigate the coordination environment of cations within the crystal lattice.

Main Methods:

• Synthesis was performed using neodymium(III) oxide, neodymium(III) fluoride, and tungsten trioxide in fused silica ampoules.
• Single crystals were obtained as a byproduct of an attempted synthesis of fluoride derivatives.
• Crystal structure was determined using X-ray diffraction analysis.

Main Results:

• Violet, platelet-shaped single crystals of Neodymium(III) ortho-oxidotungstate(VI) were obtained.
• The compound crystallizes in the defect scheelite type structure.
• A trigonal dodecahedral coordination of oxide anions around Nd3+ cations and tetrahedral coordination around W6+ cations were observed.

Conclusions:

• Neodymium(III) ortho-oxidotungstate(VI) can be synthesized under specific conditions as a byproduct.
• The defect scheelite structure provides insights into the formation of rare-earth tungstates.
• The unique coordination geometry may influence the material's properties.