Preparation and luminescence properties of Gd₃Ga₅O₁₂ nanocrystalline garnet

Chem. Met. Alloys 4 (2011) 77-80

https://doi.org/10.30970/cma4.0162

L. KOSTYK, A. LUCHECHKO, S. VARVARENKO, O. TSVETKOVA

Nanocrystalline Gd₃Ga₅O₁₂ and Gd₃Ga₅O₁₂:Tb³⁺ phosphors were obtained by sintering precursors, which had been prepared by the co-precipitation method. X‑ray diffraction (XRD), atomic force microscopy (AFM), and X‑ray luminescence spectra were used to characterize the synthesized nanocrystalline garnet. The XRD results revealed that the samples begin to crystallize at 750 °C and a fully crystallized pure Gd₃Ga₅O₁₂ phase could be obtained at 850 °C. The AFM images indicate that the phosphor powders contain aggregates of grain-like particles. Under X-ray excitation the Gd₃Ga₅O₁₂:Tb³⁺ phosphor showed the characteristic green emissions of Tb³⁺ (⁵D₄®⁷F_6,5,4,3 transitions). A comparison between X-ray luminescence spectra of pure and Tb³⁺-doped Gd₃Ga₅O₁₂ samples prepared by solid-state reaction and by the co-precipitation method was made.

2D AFM image of Gd₃Ga₅O₁₂ nanopowder calcined at 850°C.

Keywords

Nanocrystalline garnet Gd₃Ga₅O₁₂ / Co-precipitation / Rare-earth ion / X-ray luminescence