Synthesis and evolution of crystalline garnet phases in Y₃Sc_{5–<b><i>x</i></b>}Ga_{<b><i>x</i></b>}O₁₂

Abstract

Mixed-metal oxides with the composition Y3Sc x Ga5− x O12 (x = 2.0, 2.1, 2.2, 2.25, 2.3, 2.4, 2.5, and 3.0) have been prepared by an aqueous sol–gel method. The effects of scandium substitution on the garnet phase formation were studied by IR spectroscopy and X-ray powder diffraction (XRD). The XRD data indicate that single-phase Y3Sc x Ga5− x O12 ceramic samples were obtained for x = 2.0, 2.1, 2.2, 2.25, 2.3, and 2.4. The results also show that the formation of Y3Sc x Ga5− x O12 garnets depends on the molar ratio of scandium and gallium in the investigated composition, and consequently on the mean cationic radius at the Al3+ sites. The variation of lattice parameters for the Y3Sc x Ga5− x O12 phases with different x is reported.