Microwave-assisted Combustion Synthesis of (GdxY2-x) O3:Eu3+ Nanoparticles

(GdxY2-x)O3:Eu3+ nanoparticles were synthesized from stoichiometric metal nitrates mixture (oxidizer) and glycine (fuel) by microwave-assisted combustion method. (GdxY2-x)O3:Eu3+ nanoparticles were fully crystalized in solution combustion step by microwave irradiation. These nanoparticles were thermally treated at 300, 500, 700, 900, and 1100 °C for about 30 min to release the combustion-induced stresses. The nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive X-ray (EDX), and photoluminescence spectroscopy (PL) techniques. Based on the XRD spectra, the as-synthesized sample was crystalline and single-phase. The crystallinity of nanoparticles was further improved after additional thermal treatment. The main PL peaks intensity (PLI) at 612 and 590 nm (relating to 5D0-7F2 electric bipolar and 5D0-7F1 magnetic dipole transitions, respectively) were increased upon thermal treatment above 300 °C. The PLI was increased about twice of the as-synthesized sample upon thermal treatment at 1000 °C. The Chromaticity coordinates diagram of the emission were evaluated based on the 1931 CIE chromaticity diagram. TEM images confirmed the grain growth from ~25 nm to over 100 nm after thermal treatment. The substitution of Eu3+ instead of Y3+ or Gd3+ was also confirmed by EDX point analysis in (GdxY2-x)O3:Eu3+ structure. Crystallographic planes of the synthesized samples were investigated using SAED patterns. Crystallinity of samples with increasing the heat-treatment temperature was promoted. Also AFM images confirm the enhancement of particles size with increasing temperature.