Sc2(MoO4)3 and Sc2(WO 4)3: Halide flux growth of single crystals and 45Sc Solid-state NMR

Balamurugan S, Rodewald UC, Harmening T, Van Wüllen L, Mohr D, Eckert H, Pöttgen R

Zusammenfassung

Single crystals of Sc2(TO4)3 with T = Mo and W were synthesized from Sc2O3, MoO3, and WO3 at 1223 K in NaCl / KCl as solvent. Both structures were refined from X-ray diffractometer data: Pbcn, a = 1325.1(1), b = 954.9(1), c = 964.4(1) pm, wR2 = 0.0425, 2097 F2, 79 variables for Sc2(MoO4)3 and a = 1332.9(9), b = 959.4(7), c = 967.9(2) pm, wR2 = 0.0384, 1971 F2, 79 variables for Sc2(WO4)3. The structures consist of a three-dimensional network of corner-sharing ScO6/2 octahedra and two crystallographically independent TO4/2 tetrahedra. 45Sc MAS NMR spectra show sharp single resonances in accordance with the crystallographic data. The quadrupolar interaction parameters obtained from a simulation of the full 45Sc MAS NMR spectra are found to be in good agreement with those obtained from DFT calculations of the electric field gradient.