Low Temperature Synthesis of Luminescent RE2O3:Eu3+Nanomaterials Using Trimellitic Acid Precursors

Ivan G N Silva,Hermi F Brito,Oscar L Malta,Ercules E S Teotonio,Wagner M Faustino,Maria C F C Felinto,Danilo Mustafa

doi:10.5935/0103-5053.20150314

Abstract

[RE(TLA)·(H2O)n:Eu3+] (RE3+: Y, Gd and Lu; TLA: trimellitic acid) precursor complexes were synthesized by an one step aqueous co-precipitation method. After annealing for 1 h, RE2O3:Eu3+ nanophosphors were formed through the benzenetricarboxylate low temperature thermolysis method (500-1000 oC). The compounds were characterized by using different techniques [elemental analysis (CHN), Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG/DTG), X-ray powder diffraction (XPD) and scanning electron microscope (SEM)]. The XPD data indicated that the Y2O3:Eu3+ materials have crystallite size range from 11 to 62 nm. The SEM and transmission electron microscopy (TEM) images show that the annealed materials keep morphological similarities with the precursor complexes. The photoluminescence properties were studied based on the excitation and emission spectra, and luminescence decay lifetimes of the 5D0 emitting level of the Eu3+ ion. The experimental intensity parameters (Ωλ), lifetimes (τ), as well as radiative (Arad) and non-radiative (Anrad) decay rates were calculated and discussed. The RE2O3:Eu3+ phosphors (RE: Y3+ and Lu3+) annealed at 500 to 1000 oC have emission quantum efficiency (intrinsic quantum yield) values from 60 to 82%, indicating that this material can be potentially used for optical markers applications.

Highlights

Polycarboxylate ligands have a wide variety of structure providing large range of chemical properties when combined with metal ions
The organic moiety decomposition of the complexes presents only one single-step between 450 and 570 °C. It was used annealing temperature of 500 °C during 1 h, in order to eliminate all the organic part leading to formation of the RE2O3:Eu3+ luminescent material
The narrowing of the diffraction peaks of RE2O3:Eu3+ (1.0 mol%) (RE3+: Y, Gd and Lu) phosphors presented in the X-ray powder diffraction (XPD) patterns (Figure 3) as function of the annealing temperature, indicates that the crystallite size increases from

Summary

Introduction

Polycarboxylate ligands have a wide variety of structure providing large range of chemical properties when combined with metal ions. The RE2O3:Eu3+ materials originated from the [RE(TLA)] precursor complexes present similar chemical behavior compared to the sesquioxides prepared from the [RE(TMA)] complexes as reported by Silva et al.[23]

Results

Conclusion