The substitution of aluminum with scandium in the mixed yttrium aluminum scandium garnets, Y 3 Sc x Al 5--x O 12 (x ¼ 0, 0.05, 0.5, 1.5), was studied for the first time using 27 Al magic angle spinning (MAS), multiple quantum (MQ) MAS NMR, and 45 Sc MAS NMR. The aluminum and scandium quadrupole coupling constants and isotropic chemical shifts were evaluated for all garnets under study. 27 Al 2D spectra evidenced variation of the isotropic shifts over the aluminum sites in the mixed garnets.

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We report on the first achievement of CW oscillation in Yb3+:Lu2O3 ceramic lasers (2F5/2 → 2F7/2 channel) under LD‐pumping at 0.976 µm wavelength, as well as present of the thickness of grain boundary layers in Lu2O3 ceramics was estimated under non‐equilibrium acoustic phonon propagation kinetics at helium temperature (2.4–3.8 K). (© 2006 by Astro, Ltd. Published exclusively by WILEY‐VCH Verlag GmbH & Co. KGaA)

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27Al NMR studies of the Y3—xYbxAl5O12 mixed garnets were performed. The magnetic moment of Yb3+ ions in the garnets was determined. The quadrupole coupling constants were calculated for Al in a‐ and d‐positions. It was shown that the mixed garnets with x = 0.75 and 1.00 should be treated as partially ordered solid solutions. A model of substitutional ordering for these mixed garnets was suggested.

The character of the substitutional order, the chemical shift, and the nuclear quadrupole coupling in the mixed yttrium-lutetium aluminium garnets Y3-xLuxAl5O12 (0⩽x⩽3) were studied for the first time using 27Al magic angle spinning (MAS) and multiple quantum (MQ) MAS nuclear magnetic resonance (NMR). The relatively narrow distribution of the isotropic NMR line shifts, revealed by MQ MAS NMR, in crystals with compositions x = 0.75 and x = 1 compared to mixed garnets of other compositions showed that these crystals are partially ordered solid solutions. The aluminium quadrupole coupling constants and isotropic chemical shifts were evaluated for all garnets under study.