Study on the formation of sol-gel derived calcium, lithium and lanthanide element (Ln - Ce, Eu, Tb) substituted yttrium gallium/aluminium garnets Y3-x-y-zCaxLiyLnzGa5-mAlmO12: Novel insight to high-entropy compounds

High-entropy garnet crystal structure compounds with novel chemical compositions (Y3-x-y-zCaxLiyLnzGa5-mAlmO12) (Ln – Ce, Eu, Tb) have been synthesized by an aqueous sol-gel method. The multinary substitution of yttrium by calcium, lithium and lanthanide element (cerium, europium and terbium) effects in these gallium/aluminium garnets have been investigated. The intermediates and synthesized end products were characterized by thermal analysis (TG/DTG/DSC), powder X-ray diffraction analysis (XRD), FT-IR spectroscopy and scanning electron microscopy (SEM). The different effects of multinary substitution with calcium, lithium and lanthanide ions in Y3-x-y-zCaxLiyLnzGa5-mAlmO12 samples in comparison with single-metal substitution cases were determined from the results of XRD analysis. The XRD patterns of these samples clearly showed that single phase cubic structure garnets have been synthesized at low substitutional level of yttrium by calcium, lithium and lanthanide element (cerium, europium and terbium). The luminescent properties of (Y3-x-y-zCaxLiyLnzGa5-mAlmO12) (Ln – Ce, Eu, Tb) garnets were also investigated.