Sol–gel synthesis and characterization of sub-microsized lanthanide (Ho, Tm, Yb, Lu) aluminium garnets

Sub-microsized and nanosized holmium aluminium garnet (Ho3Al5O12, HoAG), thulium aluminium garnet (Tm3Al5O12, TmAG), ytterbium aluminium garnet (Yb3Al5O12, YbAG) and lutetium aluminium garnet (Lu3Al5O12, LuAG) powders were prepared by a simple aqueous sol–gel method using aluminium nitrate nonahydrate, lutetium oxide, thulium oxide, holmium oxide and ytterbium oxide as starting materials. Ethane-1,2-diol was used as complexing agent. The powder X-ray diffraction (XRD) patterns of the specimens sintered at 1000 °C revealed the formation of monophasic HoAG, TmAG, YbAG, and LuAG. The phase composition of the samples was also characterized by infrared (IR) spectroscopy. Microstructural features of the polycrystalline garnets were studied by scanning electron microscopy (SEM).

Graphical abstractThe monophasic lanthanide (Ho, Tm, Yb, Lu) aluminium garnets were prepared by sol-gel method. The recorded optical reflectance spectra of garnet samples showed that these compounds are excellent candidates as host material for advanced optical applications.Figure optionsDownload full-size imageDownload high-quality image (86 K)Download as PowerPoint slideHighlights► The homogeneous RE-Al-O (RE = Ho, Yb, Tm, Lu) gels obtained in an aqueous medium. ► The sol-gel synthesis yielded the single-phases lanthanide aluminium garnets. ► IR results of synthesized RE3Al5O12 garnets fully supported the XRD results. ► The surface microstructure of RE3Al5O12 garnets depends on the nature of lanthanide. ► The Ho3Al5O12, Tm3Al5O12, Yb3Al5O12 and Lu3Al5O12 are optical materials.