Combined Approach for the Structural Characterization of Alkali Fluoroscandates: Solid-State NMR, Powder X-ray...

Area of Science:

• Solid-state chemistry
• Materials science
• Inorganic chemistry

Background:

• Fluoroscandate compounds are crucial in various applications.
• Detailed structural and local environment characterization is essential for understanding their properties.

Purpose of the Study:

• To determine the crystal structure of K5Sc3F14.
• To investigate the local structures of NaScF4, Li3ScF6, KSc2F7, and Na3ScF6.
• To establish NMR spectroscopic fingerprints for scandium and fluorine in these materials.

Main Methods:

• Powder X-ray diffraction (PXRD) with Rietveld refinement for K5Sc3F14.
• Solid-state 19F and 45Sc Nuclear Magnetic Resonance (NMR) spectroscopy for local structure analysis.
• First-principles calculations (CASTEP) for NMR parameter prediction.

Main Results:

• The crystal structure of K5Sc3F14 was fully determined.
• Defined chemical shift ranges for six- and seven-coordinated scandium.
• Determined chemical shift ranges for bridging and terminal fluorine atoms.
• Achieved good agreement between calculated and experimental NMR data.

Conclusions:

• Solid-state NMR, combined with PXRD, provides detailed structural insights into fluoroscandates.
• Computational methods show strong potential for aiding spectroscopic assignments in solid-state 45Sc NMR.
• This work establishes a foundation for further research into scandium-based materials.