One-Step Synthesis and Luminescent Properties of Nanocrystalline YVO4:Eu3+ Powders

2008 ◽  
Vol 8 (3) ◽  
pp. 1228-1233 ◽  
Author(s):  
Deyan Kong ◽  
Zhenling Wang ◽  
Cuikun Lin ◽  
Piaoping Yang ◽  
Zewei Quan ◽  
...  
Keyword(s):  
Bulk Material ◽  
Luminescent Properties ◽  
Photoelectron Spectra ◽  
Synthesis Process ◽  
Luminescence Spectra ◽  
Luminescence Decay Curve ◽  
Xps Spectra ◽  
X Ray ◽  
Temperature Solution ◽  
Ft Ir

In this paper, nanocrystalline YVO4:Eu3+ powders have been successfully synthesized via high-temperature solution-phase synthesis process. The nanocrystalline YVO4:Eu3+ particles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV/Vis absorption spectra and luminescence spectra, luminescence decay curve and Fourier transform infrared (FT-IR), X-ray photoelectron spectra (XPS) respectively. The as-prepared nanocrystalline YVO4:Eu3+ particles are well crystallized with ellipsoidal morphology. The emission of YVO4:Eu3+ particles show emission originating from the 5D0 level, with 5D0–7F2 at 616 nm as the most prominent group. The excitation spectrumfits basically with the absorption spectrumfromthe vanadate ions. FT-IR and XPS spectra indicate that the surface ligands of nanocrystalline particles were oleic acid and oleylamine. The lifetime for the luminescence of Eu3+ in the as-prepared YVO4:Eu3+ samples are shorter than that of the bulk material due to the absorption of organic ligands on the nanoparticle surface.

Luminescent Properties of Zn2SiO4:Eu3+,Dy3+ Phosphors via Sol-Gel Process

2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi
Keyword(s):  
Thermal Analysis ◽  
Ir Spectra ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Ft Ir

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.

Preparation and Characterization of Ni2+-Montmorillonite/Polyvinyl Alcohol Water-Soluble Nanocomposite Film

2005 ◽  
Vol 13 (8) ◽  
pp. 839-846 ◽  
Author(s):  
Li-Ping Wang ◽  
Yun-Pu Wang ◽  
Fa-Ai Zhang
Keyword(s):  
Polyvinyl Alcohol ◽  
Photoelectron Spectroscopy ◽  
Thermal Characteristics ◽  
Water Soluble ◽  
Scanning Calorimetry ◽  
Xps Spectra ◽  
X Ray ◽  
Alcohol Water ◽  
Ft Ir ◽  
Silicate Layers

A new type of nano-composite film was prepared from polyvinyl alcohol, Ni2+-montmorillonite (Ni2+-MMT), defoamer, a levelling agent and a plasticizer. Its thermal characteristics were studied by Differential Scanning Calorimetry (DSC). The intermolecular interactions were measured by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), and the tensile strength (TS) and elongation at break (%E) were measured. The microstructures were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). FT-IR and XPS spectra indicated that cross-linking has taken place between PVA and Ni2+-MMT. XRD and AFM indicate that the PVA molecules had inserted themselves into the silicate layers of MMT, exfoliating them and dispersing them randomly into the PVA matrix. Compared to pure PVA film, the TS of the films was increased and %E decreased when the Ni2+-Montmorillonite was added and the dissolution temperature of the film was also reduced.

An approach for the efficient immobilization of 79Se using Fe-OOH modified GMZ bentonite

2020 ◽  
Vol 108 (2) ◽  
pp. 113-126
Author(s):  
Junqiang Yang ◽  
Keliang Shi ◽  
Xuejie Sun ◽  
Xiaoqing Gao ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Low Cost ◽  
High Mobility ◽  
Synthesis Process ◽  
Gmz Bentonite ◽  
Filling Material ◽  
Xps Spectra ◽  
Ft Ir ◽  
High Level ◽  
Critical Consideration ◽  
Formation Of Complexes

AbstractBecause of high mobility, the immobilization of long-lived fission product 79Se (often existed as 79Se(IV) and 79Se(VI) anions) is a critical consideration in the repository of high-level radioactive waste. In this work, a Fe-OOH modified bentonite (Fe-OOH-bent) was synthesized as a potential filling material in the repository site for effective adsorption and present the migration of different species of 79Se. The adsorbent was characterized using FT-IR, XRD, XFS, zeta potential and BET to clarify its physical properties, compositions and structures. A good thermal and radiation stabilities of Fe-OOH-bent was confirmed by its stable uptake ratio for Se(IV) and Se(VI) compared to original samples. The batch experimental results show that Se(IV) and Se(VI) can be efficiently removed from aqueous by Fe-OOH-bent within 60 min with maximum adsorption capacities of 68.45 mg/g for Se(IV) and 40.47 mg/g for Se(VI) in the optimal conditions, indicating its high potential application in consideration of its simple synthesis process, low cost and high adsorption capacity in view of immobilization of 79Se. The surface species and variation of oxide state of Fe as well as Se(IV) and Se(VI) onto Fe-OOH-bent were investigated by XPS analysis. The values of relative area of Se(IV)–O and Se(VI)–O in XPS spectra followed the same tendency as their adsorption ratio with the variation of system pH, suggesting that the formation of complexes between selenium species and Fe-OOH-bent surface.

XPS Spectra of Spin-Triplet Cobalt(III) Complexes

1979 ◽  
Vol 34 (10) ◽  
pp. 1468-1470 ◽  
Author(s):  
Dennis G. Brown ◽  
Ulrich Weser
Keyword(s):  
Triplet State ◽  
Spectral Region ◽  
Magnetic Moments ◽  
Binding Energies ◽  
Photoelectron Spectra ◽  
Xps Spectra ◽  
Satellite Structure ◽  
X Ray ◽  
Spin Triplet

Abstract The X-ray photoelectron spectra of cobalt(III) complexes in an unusual spin triplet state are reported. The binding energies in the 2P spectral region are somewhat low and the spectra exhibit rather strong satellite structure. The Co 2P1/2-CO 2P3/2 separations and satellite intensities appear to be related to the magnetic moments of the complexes as has been suggested previously for cobalt(II) compounds.

The hydrogen bonding structure of adsorbed water on silver iodide and Feldspar minerals

2020 ◽  
Author(s):  
Markus Ammann ◽  
Huanyu Yang ◽  
Luca Artiglia ◽  
Anthony Boucly
Keyword(s):  
Hydrogen Bonding ◽  
Water Vapor ◽  
Silver Iodide ◽  
Adsorbed Water ◽  
Photoelectron Spectra ◽  
Water Molecules ◽  
Xps Spectra ◽  
X Ray ◽  
Bonding Structure ◽  
Electron Yield

<p>The hydrogen bonding structure of adsorbed water on a solid substrate may control deposition nucleation, which is a pathway of heterogeneous ice nucleation. Hydrogen bonding of water molecules is also controlling the interface between the solid and liquid water relevant for other heterogeneous freezing modes. The hydrogen bonding structure may be affected by short and long-range interactions between the substrate and the water molecules nearby. Electron yield near edge X-ray absorption fine structure (NEXAFS) spectroscopy at the oxygen K-edge is used to experimentally explore the difference between the hydrogen bonding structure of interfacial H<sub>2</sub>O molecules under different conditions of temperature and water vapor pressure. Experiments reported in this work were performed at the in-situ electron spectroscopy endstation at the ISS beamline at the Swiss Light Source (PSI, SLS). We report electron yield oxygen K-edge NEXAFS spectra and X-ray photoelectron spectra from silver iodide (AgI) particles and milled feldspar samples exposed to water vapor at high relative humidity, but subsaturated with respect to ice. AgI serves as a well-studied reference case; and it contains no oxygen in its lattice, which simplifies the analysis of NEXAFS spectra at the O K-edge. The feldspar samples include a potassium containing microcline and a sodium-rich albite. The analysis of the NEXAFS spectra indicate rather tetrahedrally coordinated adsorbed water molecules on AgI particles. On the feldspars, the mobility of ions, as directly observed by the XPS spectra appears to have a strong impact on the hydrogen bonding structure, as apparent from substantial differences between samples previously immersed in pure water or as prepared. To sum up, we attempt to understand the behavior of the hydrogen bonding structure, which provides rich information about the arrangement of water molecules in the vicinity of a solid surface, that is linked to the ability of the solid to induce ice formation.</p>

Photoluminescence Characteristics of Sol–Gel Derived ZnTiO3 Doped with Ni2+ Ion

2013 ◽  
Vol 544 ◽  
pp. 360-363 ◽  
Author(s):  
You Hua Yu ◽  
Meng Xia ◽  
Li Li Liu ◽  
Wei Jie Wu
Keyword(s):  
Sol Gel ◽  
Luminescent Properties ◽  
Host Lattice ◽  
Deionized Water ◽  
Luminescence Spectra ◽  
X Ray Diffraction ◽  
Spectra Analysis ◽  
X Ray ◽  
Water As Solvent ◽  
Sol Gel Process

ZnTiO3 doped with Ni 2+ ion has been prepared at a relatively low temperature of 600°C from the precursor derived from sol-gel process using deionized water as solvent. X-ray diffraction analysis indicates that the doped samples exhibit a hexagonal ZnTiO3 structure. From the luminescence spectra analysis, the introduction of Ni2+ ions into ZnTiO3 results in novel luminescent properties. And the relative intensity of the bands varies with the concentration of Ni2+ ions. It is demonstrated that the Ni2+ ion has taken the place of Zn2+ ion in the host lattice of ZnTiO3.

Effect of Annealing on Valence Electronic States Related to Mn Ions of La0.67Sr0.33MnO3 Films

2017 ◽  
Vol 893 ◽  
pp. 113-117
Author(s):  
Rui Kun Pan ◽  
Yang Li ◽  
Fan Fang ◽  
Wan Qiang Cao ◽  
Yun Bin He
Keyword(s):  
Surface Defects ◽  
Vacuum Annealing ◽  
Photoelectron Spectra ◽  
Xps Spectra ◽  
X Ray ◽  
Lsmo Film ◽  
Peak Fitting ◽  
Binding Energy Peak ◽  
Energy Peak ◽  
Before And After

La0.67Sr0.33MnO3 (LSMO) films were prepared on SrTiO3 single-crystal substrates by the pulsed laser deposition method. X-ray photoelectron spectra (XPS) were measured for the LSMO films as-prepared and annealed in vacuum, respectively. Multiple peak fitting for Mn 2p3/2 XPS spectra shows that Mn3+ and Mn4+ proportionally decrease on the surface of the LSMO film annealed in vacuum compared with the as-prepared film. And the saturation magnetization (Ms) slightly decreases. Analysis indicates that a small amount of Mn2+, as surface defects of LSMO films, hardly changed after vacuum annealing. The total of Mn3+, Mn4+ and the low-binding energy peak (LEP) remains unchanged before and after annealing in vacuum, which suggests that LEP should be related with Mn3+ and Mn4+ when the magnetic properties are considered.

scholarly journals Effect of sulfur on the scintillation properties of mixed ZnSxSe1–x crystals

2018 ◽  
pp. 36-42
Author(s):  
O. G. Trubaieva ◽  
M. A. Chaika ◽  
O. V. Zelenskaya ◽  
A. I. Lalayants ◽  
S. N. Galkin
Keyword(s):  
Directional Solidification ◽  
Sulfur Content ◽  
Light Output ◽  
Luminescent Properties ◽  
High Energy ◽  
Luminescence Spectra ◽  
Bulk Crystals ◽  
X Ray ◽  
Basic Properties ◽  
Better Than

ZnSxSe1–x based luminescent materials are promising for use as X-ray and g-ray detectors. The main advantage of ZnSxSe1–x crystals is the possibility of making of solid solutions over an entire X-range. It was found that varying the composition of ZnSxSe1–x crystals can change their luminescent properties. Many studies were focused on obtaining ZnSxSe1–x mixed crystals, most using a vapour phase growth methods, and only some of works used the directional solidification. The directional solidification techniques allow growing large ZnSxSe1–x crystals for high-energy particles detectors. Practical use, however, requires the knowledge about luminescent properties of ZnSxSe1–x bulk crystals. This study reports the effect of sulfur content on basic properties of ZnSxSe1–xx bulk crystals grown by Bridgman-Stockbarger method. Six different compounds were studied: ZnS0.07Se0.93, ZnS0.15Se0.85, ZnS0.22Se0.78, ZnS0.28Se0.72, ZnS0.32Se0.68, ZnS0.39Se0.61. The ZnSe(Al) and ZnSe(Te) crystals grown at the similar conditions were used as reference. X-ray luminescence was studied using РЕИС-И (REIS-I) X-ray source (Cu, U = 10—45 kV). КСВУ-23 (KSVU-23) spectrophotometer was used to analyse the emission spectra. The afterglow level h(%) was determined by Smiths Heimann AMS-1 spectrophotometer at excitation by such X-ray and g-ray sources as 123Cs and 241Am (59.5 keV). Light output is one of the main characteristics of the scintillator, which determines its quality as a detector. The ZnSxSe1-x crystals demonstrated increase in the intensity of X-ray induced luminescence spectra with increasing of sulfur content and reached maximum for ZnS0.22Se0.78 composition. Light output of ZnSxSe1–x bulk crystals are higher than those of ZnSe(Te) and ZnSe(Al) commercial crystals. Moreover, thermal stability of scintillation light output of ZnSxSe1–x bulk crystals are also better than those. This investigation has revealed that basic properties of ZnSxSe1–x based scintillation detectors are better than those of ZnSe(Te) and ZnSe(Al).

scholarly journals Preparation and study of the luminescent glass-ceramics based on barium iodide activated with Eu2+

2019 ◽  
pp. 38-44
Author(s):  
Tatsiana A. Salamakha ◽  
Ekaterina E. Trusova ◽  
Yauhen U. Tratsiak
Keyword(s):  
Water Vapor ◽  
Diffraction Analysis ◽  
Glass Ceramics ◽  
Luminescent Properties ◽  
Original Method ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barium Iodide ◽  
Spectral Luminescent Properties

In this paper an original method for obtaining glass-ceramics based on barium iodide powder activated with Eu2+ is proposed, their structural and spectral-luminescent properties are investigated. X-ray diffraction analysis has evidenced that glass-ceramics containing BaI2 ∙ 2H2O and BaI2 are formed when 50 mas. % of the starting iodide powder is used in the synthesis process. The possibility of using glass-ceramics for preventing the contact of iodide powder with water vapor has been confirmed.

The Preparation and Characterization of Fluorinated Graphene Oxide with Different Degrees of Oxidation

2018 ◽  
Vol 792 ◽  
pp. 89-97
Author(s):  
Xiao Feng Zhao ◽  
Zi Li Yu ◽  
Cong Li Fu ◽  
Xiu Li Wang
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Property ◽  
Graphene Derivatives ◽  
Ft Ir ◽  
Fluorinated Graphene ◽  
Fluorinated Graphene Oxide

For many excellent graphene derivatives, tailoring the material properties is crucial to get a broader application. In the present work, a series of fluorinated graphene oxide (FGO) with various oxidation degree were synthesized using a modified Hummers method at different reaction temperatures. The structure and property of FGO were analyzed by X-ray diffraction (XRD), Fourier transform infra-red spectra (FT-IR), X-ray photoelectron spectra (XPS) and Zeta potential analysis. The results indicate that the oxygen contents range from 5.61 % to 21.96 % in FGO can be tuned by altering the reaction temperatures. The oxygen in FGO is presented mainly in the form of epoxide and carboxyl groups. With increasing reaction temperature from 50 °C to 90 °C, the oxygen content in FGO decreases and thicker multilayered FGO is formed with lower dispersibility.

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