Optical Characterization of Eu-Doped and Undoped Gd₂O₃ Nanoparticles Synthesized by the Hydrogen Flame Pyrolysis Method

Abstract

Rare-earth-doped nanoparticles are promising materials for fluorescent labeling, as they are characterized by a high Stokes shift, narrow emission spectra, long lifetimes, minimized photobleaching, and low toxicity. We examined the structural and optical properties of europium-doped gadolinium oxide nanoparticles synthesized by the flame pyrolysis method, with specific emphasis on full spectral characterization and fluorescence kinetics. The emission-excitation characterization revealed the presence of predominantly monoclinic but also highly luminescent cubic phases with a prominent oxygen-to-europium charge-transfer band in the 230-260 nm range. A broad emission band in the visible region, corresponding to a similar band in undoped Gd(2)O(3), related to the matrix surface defects, was observed in time-gated spectroscopy of doped nanopowders. All of the examined nanopowders showed very short decay components, on the order of 2 ns, and much longer millisecond decay times characteristic of lanthanide ions. At intermediate times, on the order of 20-100 ns, a complex behavior of the decay was observed, indicative of progressive energy transfer to the lanthanide ion, which varied with different intrashell transitions. Structural characterization data by means of XRD measurements allowed for unambiguous determination of the Eu:Gd(2)O(3) crystallographic structure and cell dimensions to be consistent with a predominantly monoclinic phase.

Magnetic/luminescent core/shell particles synthesized by spray pyrolysis and their application in immunoassays with internal standard

“…The XRD spectrum of the primary magnetic particles reveal the presence of FeO 4 iron oxide along with other phases ( figure 5(a)). The XRD spectrum of the secondary core/shell particles ( figure 5(b)) shows a pattern close to the monoclinic Gd 2 O 3 phase ( figure 5(d)), which is in agreement with recently published results [33]. Some additional peaks (e.g.…”

Luminescence Properties of Redispersible Tb3+‐Doped GdPO4 Nanoparticles Prepared by an Ethylene Glycol Route

“…It indicates the occurrence of an energytransfer process from the Gd 3+ to the Tb 3+ ion. The remaining peaks [i.e., 7 . [33] It is to be noted that the second harmonic generation of 545 nm will give approximately 273 nm.…”

One‐Pot Synthesis of Luminescent Polymer‐Nanoparticle Composites from Task‐Specific Ionic Liquids

“…GdF 3 acts as a host matrix, diluting the active ions to reduce concentration quenching, with the added advantage of Gd 3 + effi ciently transferring energy to Eu 3 + and Tb 3 + , [ 28 ] and being a promising potential candidate for the conversion of VUV (vacuum UV) radiation. [ 21,29 ] Indeed, Eu 3 + doped GdF 3 has already been reported as a quantum-cutting material, capable of quantum yields greater than unity. [ 21 ] Combining this with a wide choice of anions gives us the possibility to design an ionic liquid to a specifi c purpose or task, hence the commonly coined term task-specifi c ionic liquids.…”