27Al nuclear magnetic resonance studies of the Y3-xLuxAl5O12 mixed garnets

The character of the substitutional order, the chemical shift, and the nuclear quadrupole coupling in the mixed yttrium-lutetium aluminium garnets Y3-xLuxAl5O12 (0 less than or equal to x less than or equal to 3) were studied for the first time using Al-27 magic C, 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.