PbO/PbF2 Flux Growth of YScO3 and LaScO3 Single Crystals - Structure and Solid-State NMR Spectroscopy

Well-shaped small single crystals of the orthorhombic perovskites YScO3 and LaScO3 were grown from mixtures of the corresponding sesquioxides RE2O3 in PbO/PbF2 fluxes. Both structures were refined from single-crystal diffractometer data: GdFeO3-type, Pnma, a = 570.68(7), b = 789.3(1), c = 542.44(7) pm, wR2 = 0.0363, 448 F-2 values for Y0.96Sc02.94, and a = 579.68(9), b = 810.3(2), c = 568.3(1) pm, wR2 = 0.0387, 513 F-2 values for La0.94ScO2.91, with 32 variables per refinement. The 4c rare-earth sites of both perovskites show small defects which are charge-compensated by defects on both oxygen sites, leading to the compositions La0.94ScO2.91 and Y0.96ScO2.94 for the investigated crystals. The rare-earth sites have been characterized by Y-89 and Sc-45 magic-angle spinning (MAS) NMR. The Sc-45 quadrupolar interaction parameters extracted from these spectra by simulations are found to be in good agreement with those obtained from DET calculations of the electric field gradient.