Europium-doped Yttrium Oxide Research Articles

Characterization of europium doped yttrium nano-oxide prepared by plasma electrolysis in nitrate solution under air atmosphere at room temperature

Europium-doped yttrium oxide is widely used because its unique optical properties, excellent thermal stability, and chemical stability. This paper reports a process for preparing a Y2O3:Eu3+ red fluorescent material through plasma discharge electrolysis at room temperature in a normal atmosphere and a 0.38 M Y(NO3)3 - 0.02 M Eu(NO3)3 mixed rare earth nitrate solution. Several techniques, including emission spectroscopy, X-ray diffraction, TG-DSC thermal analysis, Fourier transform infrared spectroscopy and photoelectron spectroscopy, were performed to characterize the electrolysis process and the obtained products. The results show that the electrolytic products were mainly composed of Y(OH)3, the electrolytic hydroxide products were not obviously granular, and Eu was uniformly distributed in the products. After heat treatment at 400–900 °C, cubic phase yttrium oxide was formed, and the products were irregular spherical, with particle sizes between 30 and 200 nm. After annealing at 800 °C, the products showed strong red emission at 612 nm, corresponding to 5D0→7F2 excitation. In addition, charge transfer band (CTB) absorption was observed in the excitation spectrum, and the emission spectra of fluorescent materials also showed some sharp emission bands generated by the 5D0→7FJ (J = 0,1,3,4) transition. The colour coordinate of the Y2O3:Eu3+ powder produced by plasma electrolysis is close to the standard red coordinate, showing excellent colour properties.

Flexible droplet printing of prominently luminescent patterns of europium-doped yttrium oxide nanospheres

Flexible techniques for producing luminescent patterns with high-resolution and moderate efficiency at the microscale are potentially important for pattern display, customized anti-counterfeiting and data security. An innovative droplet-based aerosol jet printing procedure has been developed for the creation of prominently luminescent patterns of europium-doped yttrium oxide (Y2O3:Eu3+) inorganic phosphors in case of a rather low calcining temperature. Microscale luminescent patterns of pomegranate-shaped Y2O3:Eu3+ nanospheres were effectively created by synchronizing the droplet deposition behavior and the microreactions therein. The deposition temperature was crucial to the pattern development accompanying a morphological transformation from dense film to spherical nanostructures by providing an anisotropic evaporation regime. The red emission of the printed luminescent patterns was nearly identical to that of the equivalents calcined at 1000 °C, indicating the possibility for future applications in flat panel display systems.

Thermal conversion of infinite coordination polymers to europium-doped yttrium oxide microspheres

• •Y 2 O 3 :Eu 3+ microspheres were obtained by calcinating infinite coordination polymers. • •A relatively low temperature (550 °C) could be used for the thermal conversion. • •An increase of luminescence intensity could be observed after calcination. • •The particles were sliced using focused ion beam (FIB) and studied by SEM. We report the synthesis and thermal conversion of an infinite coordination polymer (ICP) based on the pyrazole-3,5-dicarboxylate linker, malonate coordination modulator, and Y 3+ metallic matrix doped with 5 % of Eu 3+ . The ICP particles exhibited spherical morphology and diameters between 1.0 and 3.0 µm. Then, this sample was subjected to a calcination process in order to obtain luminescent Y 2 O 3 :Eu 3+ particles with the same spherical morphology but with smaller diameters overall (<1.5 µm). A focused ion beam (FIB) was used to slice the particles and observe their insides using SEM. While the precursor ICP particles exhibit a smooth and massive interior, the calcinated Y 2 O 3 :Eu 3+ particles show internal channels and cracks due to the combustion of the organic components. The combination of excellent luminescent behavior, spherical shape, microsize, and presence of internal channels can lead to multifunctional Y 2 O 3 :Eu 3+ microparticles for biomedicine, photonics, and catalysis applications.

Structural, compositional and luminescence studies of Y2O3:Eu3+ nanophosphor synthesized by sol-gel method

Europium doped Yttrium oxide (Y2O3) nanophosphors with different doping concentrations were synthesized by simple and efficient sol-gel method. The structural, morphological and compositional study was carried out by using XRD, FE-SEM, TEM, EDS, XPS, etc. Results demonstrated that the material is highly crystalline with cubic (body centered) structure and the particles apparently are of spherical shape with particle size around ∼10–20 nm. EDS results show the presence of Eu-impurity evenly distributed. Optimization of luminescence properties of the material by varying the concentration and annealing temperature show maximum thermoluminescence (TL) sensitivity at 1600 °C for 10.0 M% of Eu, however, maximum photoluminescence (PL) intensity was achieved after annealing the nanophosphor at 1200 °C. It exhibits a strong red emission with a sharp peak at 612 nm under excitation with UV and visible light (λex = 260, 393, 466 nm). TL studies showed four peaks at 100, 117, 139, and 301 °C. However, the first peak fades completely in a day (apparently due to low peak temperature) but the other three peaks are quite stable. The TL response was found to be linear from 120 Gy to 1.0 kGy but becomes sub-linear later in the dose range 1.0–100 kGy.

Flexible Droplet Printing of Prominently Luminescent Patterns of Europium-Doped Yttrium Oxide Nanospheres

Flexible Droplet Printing of Prominently Luminescent Patterns of Europium-Doped Yttrium Oxide Nanospheres

Hydrothermal synthesis and luminescent properties of Y2O3:Eu3+ from waste phosphors

Abstract Europium-doped yttrium oxide (Y2O3:Eu3+) phosphors were successful synthesized by hydrothermal method from waste phosphors in the presence of sodium citrate. The synthesized samples were characterized by X-ray diffraction, scanning electron microscopy and photoluminescence spectroscopy. The experimental results showed that the morphology and photoluminescent properties of the obtained samples had a strong dependence on the concentrate of sodium citrate, the addition amount of NaOH and Eu in the hydrothermal process. Well-dispersed Y2O3:Eu3+ hexagonal microdisk with average diameter of 2 μm were synthesized in the presence of 6 mol% Eu, 37.5 mmol NaOH, molar ratios of Cit3−:Y3+ = 1:1. The photoluminescence properties measurement reveled that Y2O3:Eu3+ phosphors showed a strong red emission corresponding to 5D0–7F2 (613 nm), suggesting promising application in optoelectronics.

Synthesis, processing and electron paramagnetic resonance response of Y1.98Eu0.02O3 micro rods

Innovating dosimetric materials, which includes design and development of new dosimetric materials based on rare earth oxides, is challenging. Yttrium oxide (Y[Formula: see text]O[Formula: see text] is one of the most important sesquioxides and presents crystal characteristics that enable doping with rare earth ions, making it a promising material for radiation dosimetry. This paper reports on the development and measurement of Electron Paramagnetic Resonance (EPR) signal response for Y[Formula: see text]Eu[Formula: see text]O[Formula: see text][Formula: see text]micro rods that have undergone facile low-pressure hydrothermal synthesis and bio-prototyping. As- synthesized powders with narrow sub-micrometer particle size distribution with d[Formula: see text][Formula: see text] of 584 nm exhibited a reactive surface, which led to the formation of stable aqueous suspensions by controlling the surface charge density of particles through alkaline pH adjustment. Ceramic samples with dense microstructure were formed by sintering at 1600 [Formula: see text]C for 4h at ambient atmosphere. Y[Formula: see text]Eu[Formula: see text]O[Formula: see text][Formula: see text]micro rods were irradiated using a [Formula: see text]Co source with doses from 1 to 100 kGy, and EPR spectra were measured at room temperature in X-band microwave frequencies. Sintered samples exhibited linearity of the main EPR signal response from 10 Gy to 10 kGy. Supralinearity was observed for higher doses, which is possibly ascribed to formation of more defects. Using europium as a dopant enhanced the EPR signal of yttrium rods remarkably, due to 4f–4f transitions of the Eu[Formula: see text] ion. These innovative findings make europium-doped yttrium oxide a promising material for radiation dosimetry.

Sensitive detection of free bilirubin in blood serum using β-diketone modified europium-doped yttrium oxide nanosheets as a luminescent sensor.

Free bilirubin, when present in excess in the human body, can cause a multitude of diseases and disorders and even be fatal; hence, detecting it is of paramount importance. Herein, we report a luminescence quenching-based non-enzymatic method for the convenient, reliable, and rapid detection of free bilirubin in blood serum samples using sensing films (nanosheets/PS, nanosheets-tta/PS, and nanosheets-dbt/PS) as luminescent sensors. The luminescence intensity of the sensing films is linearly related to the free bilirubin concentration. Nanosheets-tta/PS demonstrated excellent sensing properties for the sensitive and reliable detection of free bilirubin in the range of 0.0–60.0 μM with a correlation coefficient of 0.9915, as compared to nanosheets/PS or nanosheets-dbt/PS. The limit of detection for the determination of free bilirubin was 41 nM. This method can be used to design a sensor-based test spot as a medical detection device for the visual detection of free bilirubin.

Preparation and Luminescence of Europium-doped Yttrium Oxide Thin Films

Preparation and Luminescence of Europium-doped Yttrium Oxide Thin Films

Laser-synthesized Y2O3:Eu3+ nanophosphors and their stabilization in water suspensions

Europium doped yttrium oxide nanophosphors (Y2O3 doped with 5% Eu3+), which consists of spherical single-phase monoclinic particles with an average size of 17 nm, was prepared by laser synthesis. While the monoclinic material has a low efficiency of only 19% of a μm-sized commercial Y2O3:Eu product, the cubic phase after calcination at 900 °C achieves 68% despite the remaining hydroxo-groups at the surface and still small crystallite size (56 nm). An ethanolammonium salt of citric acid (Dolapix CE64) was used as a dispersant in water suspension. To estimate the stability of the dispersed phase, the electrokinetic potential and agglomerate sizes were measured as a function of pH. With this dispersant, a 30 wt% nanopowder water suspension, showing a Newtonian viscosity of about 6 mPa × s, was obtained. Maximum content of the nanopowder of about 60 wt% can be accomplished in the slurry, still fluid enough to be used to cast a highly uniform and dense ceramic green body to sinter nanostructured Y2O3:Eu3+ phosphors ceramics.

Fluorescence Enhancement of Europium-Doped Yttrium Oxide Nanosheets Modified by HTTA

Stable Eu3+ doped single-layer rare-earth oxide nanosheets sol were successfully obtained via exfoliation of layer Y(1-X)EuxOBr in n-butanol solvent. After β-diketones modifying, novel inorganic/organic luminescent hybrids were successfully synthesized. At the mean time we discovered that the main charge transfer (Eu-O) excitation bands in nanosheets were replaced by more efficient π-π* electron transition excitation band s of the organic ligands in the hybrids. The emission bands of the 5D0-7F2 electric dipole transition in hybrids were enhanced greatly.

Facile preparation and fluorescence enhancement of mesoporous Eu-doped-Y2O3 phosphors

Mesoporous europium-doped yttrium oxide phosphors were successfully synthesized by a simple Pechini sol–gel method. The prepared powders were characterized by X-ray diffraction, scanning electron microscopy, Surface area and pore size analyzer and fluorescence spectrophotometer. The XRD spectrum of the calcined samples confirm the presence of Y2O3. The surface area and pore size analyzer was employed to demonstrate the existence of mesoporous structure in these samples. The room temperature photoluminescence (PL) emissions of Y2O3:Eu samples can be observed under 245 nm excitation. PL results show that the emission intensity of as-prepared mesoporous Y2O3:Eu phosphors are higher than that of particles without special structures. Large surface area and pores play an important role in the increasing of PL intensity. The intensity ratio between 5D0 → 7F2 and 5D0 → 7F1 transitions which related to the local environment of Eu3+ were also studied.

Radioluminescence characterization of in situ x-ray nanodosimeters: Potential real-time monitors and modulators of external beam radiation therapy

Europium-doped yttrium oxide (Y2O3:Eu) has garnered considerable interest recently for its use as a highly efficient, red phosphor in a variety of lighting applications that include fluorescent lamps, plasma, and field emission display panels, light emitting diodes (LEDs), and lasers. In the present work, we describe the development of Y2O3:Eu nanoparticles for a very different application: in situ, in vivo x-ray dosimetry. Spectroscopic analyses of these nanoparticles during x-ray irradiation reveal surprisingly bright and stable radioluminescence at near-infrared wavelengths, with markedly linear response to changes in x-ray flux and energy. Monte Carlo modeling of incident flux and broadband, wide-field imaging of mouse phantoms bearing both Y2O3:Eu nanoparticles and calibrated LEDs of similar spectral emission demonstrated significant transmission of radioluminescence, in agreement with spectroscopic studies; with approximately 15 visible photons being generated for every x-ray photon incident. Unlike the dosimeters currently employed in clinical practice, these nanodosimeters can sample both dose and dose rate rapidly enough as to provide real-time feedback for x-ray based external beam radiotherapy (EBRT). The technique's use of remote sensing and absence of supporting structures enable perturbation-free dosing of the targeted region and complete sampling from any direction. With the conjugation of pathology-targeting ligands onto their surfaces, these nanodosimeters offer a potential paradigm shift in the real-time monitoring and modulation of delivered dose in the EBRT of cancer in situ.

Luminescence performance of europium-doped yttrium oxide thin films

Europium-doped yttrium oxide thin films have been deposited by a spray pyrolysis method. The crystallite sizes are calculated to be ~50nm using Scherrer׳s formula. Fourier transformed infrared spectroscopy (FTIR) reveals broad absorption with peak at 875cm−1. Surface morphology and elemental composition of the thin films are studied by a field-emission scanning electron microscope (FESEM) equipped with energy dispersive X-ray spectroscopy (EDS). The energy gap (Eg) of the thin film sample is found to be ~5.37eV. The film exhibits photoluminescence (PL) emission over 525–550nm, 585–601nm, 612nm and 620–632nm under the excitation of 240nm. Gamma (γ)-irradiated films exhibit two well-resolved thermoluminescent (TL) glows with peaks at 460 and 570K. The TL glow curves are analyzed by a glow curve shape method. The activation energy and the frequency factor are found to be, respectively, ~0.6eV, ~3×106s−1 for 460K and ~0.53eV, ~46.72×103s−1 for 570K.

Modified Eu-doped Y2 O3 nanoparticles as turn-off luminescent probes for the sensitive detection of pyridoxine.

Europium-doped yttrium oxide nanoparticles (Y2 O3 :Eu NPs) modified by captopril were prepared in aqueous solution. In this study, we report the effect of pyridoxine hydrochloride on the photoluminescence intensity of Y2 O3 :Eu NPs in pH 7.2 buffer solution. By increasing the pyridoxine concentration, the luminescence intensity of Y2 O3 :Eu NPs is quenched. The results show that this method demonstrates high sensitivity for pyridoxine determination. A linear relationship is observed between 0.0 and 62.0 μM with a correlation coefficient of 0.995 and a detection limit of 0.023 μM.

Wide-angle energy-momentum spectroscopy.

Light emission is defined by its distribution in energy, momentum, and polarization. Here, we demonstrate a method that resolves these distributions by means of wide-angle energy-momentum spectroscopy. Specifically, we image the back focal plane of a microscope objective through a Wollaston prism to obtain polarized Fourier-space momentum distributions, and disperse these two-dimensional radiation patterns through an imaging spectrograph without an entrance slit. The resulting measurements represent a convolution of individual radiation patterns at adjacent wavelengths, which can be readily deconvolved using any well-defined basis for light emission. As an illustrative example, we use this technique with the multipole basis to quantify the intrinsic emission rates for electric and magnetic dipole transitions in europium-doped yttrium oxide (Eu³⁺:Y₂O₃) and chromium-doped magnesium oxide (Cr³⁺:MgO). Once extracted, these rates allow us to reconstruct the full, polarized, two-dimensional radiation patterns at each wavelength.

Correction to “Effect of Different Surfactants on the Size Control and Optical Properties of Y2O3:Eu3+ Nanoparticles Prepared by Coprecipitation Method”

Nanoparticles of europium-doped yttrium oxide (Y2O3:Eu3+) were synthesized by coprecipitation method with use of different surfactants like butanol, hexanol, and oleic acid. The as-prepared Y2O3:Eu3+ samples were annealed at 800 °C and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and UV−visible and photoluminescence (PL) spectroscopy techniques. The nanoparticle shows cubic phase structure. Surfactant helps to inhibit or control the particle growth and avoids agglomeration of nanoparticles effectively by reducing the oxygen bridge bonds between the particles. The most intense red emission peak occurs at 614 nm at an excitation wavelength of λ = 200 nm. Nanoparticles of Y2O3:Eu3+ with a particle size of 30 nm synthesized by using oleic acid with NaCl show a 73% rise in PL intensity of the 614 nm peak.

Luminescence studies of europium doped yttrium oxide nano phosphor

Abstract Luminescence exhibiting europium doped yttrium oxide (Y 2 O 3 :Eu 3+ ) phosphor was prepared by solution combustion method, using disodium ethylene diamine tetra acetic acid (EDTA-Na 2 ) as fuel at ∼350 °C. Powder X-ray diffraction (PXRD) pattern of Y 2 O 3 :Eu 3+ revealed the cubic crystalline phase. The morphology of the samples was studied by scanning electron microscopy (SEM) and was foamy, fluffy and porous in nature. Fourier transformed infrared spectroscopy (FTIR) revealed prominent absorption with peaks at 3415, 1435, 875 and 565 cm −1 . Optical absorption studies showed the energy gap of the synthesized samples to be 5.4–5.5 eV. The photoluminescence (PL) of Y 2 O 3 :Eu 3+ exhibiting emission peak at 611 nm under the excitation of 254 nm. Thermoluminescence of γ-irradiated Y 2 O 3 :Eu 3+ showed two well resolved TL glows with peaks at 460 and 610 K and they were analyzed by glow curve shape method and the activation energies were found to be 0.421 eV and 1.016 eV respectively.

Highly Luminescent–Paramagnetic Nanophosphor Probes for In Vitro High‐Contrast Imaging of Human Breast Cancer Cells

Highly luminescent-paramagnetic nanophosphors have a seminal role in biotechnology and biomedical research due to their potential applications in biolabeling, bioimaging, and drug delivery. Herein, the synthesis of high-quality, ultrafine, europium-doped yttrium oxide nanophosphors (Y(1.9)O(3):Eu(0.1)(3+)) using a modified sol-gel technique is reported and in vitro fluorescence imaging studies are demonstrated in human breast cancer cells. These highly luminescent nanophosphors with an average particle size of ≈6 nm provide high-contrast optical imaging and decreased light scattering. In vitro cellular uptake is shown by fluorescence microscopy, which visualizes the characteristic intense hypersensitive red emission of Eu(3+) peaking at 610 nm ((5)D(0)-(7)F(2)) upon 246 nm UV light excitation. No apparent cytotoxicity is observed. Subsequently, time-resolved emission spectroscopy and SQUID magnetometry measurements demonstrate a photoluminescence decay time in milliseconds and paramagnetic behavior, which assure applications of the nanophosphors in biomedical studies.

Selected‐Control Fabrication of Multifunctional Fluorescent–Magnetic Core–Shell and Yolk–Shell Hybrid Nanostructures

The selected-control preparation of uniform core-shell and yolk-shell architectures, which combine the multiple functions of a superparamagnetic iron oxide (SPIO) core and europium-doped yttrium oxide (Y(2)O(3):Eu) shell in a single material with tunable fluorescence and magnetic properties, has been successfully achieved by controlling the heat-treatment conditions. Furthermore, the shell thickness and interior cavity of SPIO@Y(2)O(3):Eu core-shell and yolk-shell nanostructures can be precisely tuned. Importantly, as-prepared SPIO@Y(2)O(3):Eu yolk-shell nanocapsules (NCs) modified with amino groups as cancer-cell fluorescence imaging agents are also demonstrated. To the best of our knowledge, this is the first report on the selected-control fabrication of uniform SPIO@Y(2)O(3):Eu core-shell nanoparticles and yolk-shell NCs. The combined magnetic manipulation and optical monitoring of magnetic-fluorescent SPIO@Y(2)O(3):Eu yolk-shell NCs will open up many exciting opportunities in dual imaging for targeted delivery and thermal therapy.