scholarly journals Study on the Effect of γ-Irradiation on Gadolinium Oxysulfide Nanophosphors (Gd2O2S-NPs)

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Muhammad Hassyakirin Hasim ◽  
Irman Abdul Rahman ◽  
Sapizah Rahim ◽  
Muhammad Taqiyuddin Mawardi Ayob ◽  
Shamellia Sharin ◽  
...  
Keyword(s):  
Irradiation Dose ◽  
Hexagonal Phase ◽  
Spherical Shape ◽  
X Ray Diffraction ◽  
Γ Irradiation ◽  
Stark Level ◽  
Structure Morphology ◽  
Level Transition ◽  
Optical Applications ◽  
Hydrogenation Treatment

Gadolinium oxysulfide nanophosphors (Gd2O2S-NPs) have been successfully synthesized using γ-irradiation and hydrogenation treatment. The primary stage of Gd2O2S-NPs synthesis was carried out using various doses of γ-irradiation to form diverse sizes of Gd2(SO4)3 precursor, followed by hydrogenation treatment at 900°C for 2 hours to form Gd2O2S-NPs. Then, the nanophosphors were characterized for the structure, morphology, and luminescence properties through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and photoluminescence spectrometer (PL). Pure hexagonal phase of Gd2O2S-NPs was obtained with high crystallinity and without any impurities. The morphologies were observed from grain-like nanostructures transformed to spherical shape as the irradiation dose reached 40 kGy. Besides, Gd2O2S-NPs which were prepared at highest irradiation dose of 40 kGy show highest intensity of emission peak at 548 nm and corresponded to Stark level transition from the GJ6 state of Gd3+ ion. It can be emphasized that the different doses of γ-irradiation influenced the nucleation event of Gd2(SO4)3 precursor thus affecting the morphology and size particles of Gd2O2S-NPs. Hence, from the results, it can be suggested that Gd2O2S-NPs can be a promising host for optical applications.

Effect of Irradiation on the Molecular Weight, Structure and Apparent Viscosity of Xanthan Gum in Aqueous Solution

2011 ◽  
Vol 239-242 ◽  
pp. 2632-2637 ◽  
Author(s):  
Yan Jie Li ◽  
Yi Ming Ha ◽  
Feng Wang ◽  
Yong Fu Li
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Apparent Viscosity ◽  
Irradiation Dose ◽  
Xanthan Gum ◽  
Gel Permeation Chromatography ◽  
Uv Spectra ◽  
X Ray Diffraction ◽  
Γ Irradiation ◽  
Radiation Chemical

Xanthan gum samples were irradiated in aqueous solution at different doses (0-120 kGy) of 60Co γ-rays. The changes of molecular weight and structures of irradiated xanthan gum samples were investigated and characterized by using gel permeation chromatography(GPC), X-ray diffraction (XRD), fourier-transform infrared spectra (FTIR), ultraviolet–visible spectral (UV–vis) analysis and rheometer. Results showed the molecular weight decreased gradually with increasing irradiation dose. The radiation chemical yields G(d) of xanthan gum was 26.55. FTIR spectra and XRD indicated that γ-irradiation introduced no significant changes into the structure and crystal texture, but UV spectra showed a distinct absorption peak at about 265 nm, increasing with irradiation dose, which was attributed to the formation of carbonyl groups or double bond. Apparent viscosity of xanthan gum solution decreased with increasing irradiation dose and remain basically constant with the prolonging of shear time after irradiation.

Microstructure and Optical Properties of ZnS:Mn Nanocrystals

2013 ◽  
Vol 652-654 ◽  
pp. 192-196
Author(s):  
Jin Hua Ma ◽  
Chang Zheng Wang ◽  
Chang Yong Sun
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Hexagonal Phase ◽  
Blue Shift ◽  
Emission Peak ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Strong Emission ◽  
Luminescence Peak ◽  
Structure Morphology

Abstract. By using Na2S•9H2O as source precursor and citric acid as stabilizer, ZnS:Mn nanocrystallines were synthesized by solvothermal method. They were annealed at 800 oC in the charcoal powder. The structure, morphology and optical properties were investigated by using X-ray diffraction spectra (XRD), scanning electron microscopy (SEM), and Spectrofluorophotometer respectively. The results showed that all unannealed ZnS:Mn nanocrystallines were about 3~5 nm of particle size and have cubic structure, and all annealed samples were about 30-70 nm of particle size and have mixed structure of the cubic phase and hexagonal phase. Moreover, Mn2+ took the place of Zn2+ in ZnS:Mn. With the increment of Mn2+ content, there occurred a strong emission peak at about 596nm which can be attributed to the Mn2 + leap from 4T1 to 6A1. In addition, the intensity of 596nm emission peak first increased and then decreased with the increment of Mn2+ content, reaching a maximum at about 15% of Mn2+ content. After annealing Mn2+ emission peak intensity is about 20 times that before annealing, and the luminescence peak also showed slightly blue shift.

X-Ray Diffraction Analysis of the Influence of the Absorbed γ-Irradiation Dose on Ti3Al Structural Characteristics

2018 ◽  
Vol 12 (3) ◽  
pp. 480-484 ◽  
Author(s):  
M. V. Loginova ◽  
V. I. Yakovlev ◽  
A. A. Sitnikov ◽  
V. Yu. Filimonov ◽  
A. V. Sobachkin ◽  
...  
Keyword(s):  
Diffraction Analysis ◽  
Irradiation Dose ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
Γ Irradiation ◽  
X Ray

Hydrothermal Synthesis and Luminescence Property of Nanoscaled BiPO4:Eu3+ Powders

2016 ◽  
Vol 16 (4) ◽  
pp. 3827-3830 ◽  
Author(s):  
Xiaolei Shi ◽  
Yun Liu ◽  
Jin Zhang ◽  
Kun Zhang ◽  
Peng Li ◽  
...  
Keyword(s):  
Luminescence Property ◽  
Monoclinic Phase ◽  
Hexagonal Phase ◽  
Concentration Quenching ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Morphology ◽  
Effects Of Ph ◽  
Diffraction Peaks ◽  
Scanning Electron

Aseries of Bi1−xPO4:xEu3+ phosphors were prepared using a simple hydrothermal method. The effects of pH and Eu3+ doping on the structure, morphology and luminescence properties of BiPO4:Eu3+ were investigated systematically. X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM) results reveal that the as-prepared BiPO4 crystals are in a low temperature monoclinic phase (LTMP), and have a rod-like structure with a size in the range of 1–5 μm at pH 1. Increasing the pH to 2 transforms the BiPO4 to its hexagonal phase (HP), with peanut-like structures ranging from 50 to 150 nm. At pH 1, when the doping level is increased to 0.07, the phase transformation from LTMP to HP occurs, meaning that the amount of HP components increase with increasing Eu3+ doping. Furthermore, all the diffraction peaks of the Bi1−xPO4:xEu3+ can be fitted very well to HP when x = 0.11. The photoluminescence (PL) spectra suggest that orangered luminescence can be observed in the series of BiPO4:Eu3+ phosphors, and that concentration quenching occurs when x = 0.07.

Preparation and Characterization of Spinel-Type Nanocrystalline ZnFe2O4 by Radiation Method

2007 ◽  
Vol 121-123 ◽  
pp. 327-330 ◽  
Author(s):  
Zhen Li ◽  
Zheng Jiao ◽  
Ming Hong Wu ◽  
Sen Lin Wu
Keyword(s):  
Ambient Pressure ◽  
Spherical Shape ◽  
X Ray Diffraction ◽  
Spinel Type ◽  
Beam Radiation ◽  
Radiation Method ◽  
Electron Beam Radiation ◽  
Transmission Electron ◽  
Structure Morphology

A new electron beam radiation method was developed to prepare spinel-type nanocrystalline ZnFe2O4 at room temperature and ambient pressure, without any kind of catalysts. The structure, morphology and size were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), infrared spectroscopy (IR). The obtained Nanocrystalline ZnFe2O4 particles have Spinel structure, spherical shape morphology and a mean particle size distribution of 20 and 40 nm.

scholarly journals Photoluminescent Properties of Hydroxyapatite and Hydroxyapatite/Multi-Walled Carbon Nanotube Composites

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 832
Author(s):  
Edna X. Figueroa-Rosales ◽  
Javier Martínez-Juárez ◽  
Esmeralda García-Díaz ◽  
Daniel Hernández-Cruz ◽  
Sergio A. Sabinas-Hernández ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Hexagonal Phase ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multi Walled Carbon Nanotube ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites ◽  
Co Precipitation ◽  
Functionalized Mwcnts

Hydroxyapatite (HAp) and hydroxyapatite/multi-walled carbon nanotube (MWCNT) composites were obtained by the co-precipitation method, followed by ultrasound-assisted and microwave radiation and thermal treatment at 250 °C. X-ray diffraction (XRD) confirmed the presence of a hexagonal phase in all the samples, while Fourier-transform infrared (FTIR) spectroscopy elucidated the interaction between HAp and MWCNTs. The photoluminescent technique revealed that HAp and the composite with non-functionalized MWCNTs present a blue luminescence, while the composite with functionalized MWCNTs, under UV-vis radiation shows an intense white emission. These findings allowed presentation of a proposal for the use of HAp and HAp with functionalized MWCNTs as potential materials for optoelectronic and medical applications.

scholarly journals Hydrothermal Synthesis, Characterization and Exploration of Photocatalytic Activities of Polyoxometalate: Ni-CoWO4 Nanoparticles

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 456
Author(s):  
Fahad A. Alharthi ◽  
Hamdah S. Alanazi ◽  
Amjad Abdullah Alsyahi ◽  
Naushad Ahmad
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Photocatalytic Activities ◽  
Ft Ir ◽  
Photocatalytic Reactions ◽  
Cobalt Tungstate

This study demonstrated the hydrothermal synthesis of bimetallic nickel-cobalt tungstate nanostructures, Ni-CoWO4 (NCW-NPs), and their phase structure, morphology, porosity, and optical properties were examined using X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy- energy dispersive X-ray spectroscopy (SEM-EDS), high resolution Transmission electron microscopy (HR-TEM), Brunauer-Emmett-Teller (BET) and Raman instruments. It was found that as-calcined NCW-NPs have a monoclinic phase with crystal size ~50–60 nm and is mesoporous. It possessed smooth, spherical, and cubic shape microstructures with defined fringe distance (~0.342 nm). The photocatalytic degradation of methylene blue (MB) and rose bengal (RB) dye in the presence of NCW-NPs was evaluated, and about 49.85% of MB in 150 min and 92.28% of RB in 90 min degraded under visible light. In addition, based on the scavenger’s study, the mechanism for photocatalytic reactions is proposed.

Physical Properties Of Single-Phase Skutterudite Thin-Films (CoSb3 and IrSb3)

1998 ◽  
Vol 545 ◽  
Author(s):  
J. C. Caylor ◽  
A. M. Stacy ◽  
T. Sands ◽  
R. Gronsky
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Growth Parameters ◽  
X Ray Diffraction ◽  
Adhesion Properties ◽  
Rutherford Back Scattering ◽  
Phonon Component ◽  
Transmission Electron ◽  
Structure Morphology ◽  
High Vapor

AbstractBulk skutterudite phases based on the CoAs3 structure have yielded compositions with a high thermoelectric figure-of-merit (“ZT”) through the use of doping and substitutional alloying. It is postulated that further enhancements in ZT may be attained in artificially structured skutterudites by engineering the microstructure to enhance carrier mobility while suppressing the phonon component of the thermal conductivity. In this work the growth and properties of singlephase CoSb3 and IrSb3 skutterudite thin films are reported. The films are synthesized by pulsed laser deposition (PLD) where the crystallinity can be controlled by the deposition temperature. Powder X-ray diffraction (PXRD), Transmission electron microscopy (TEM) and Rutherford- Back Scattering (RBS) were used to probe phase, structure, morphology and stoichiometry of the films as functions of growth parameters and substrate type. A substrate temperature of 250°C was found to be optimal for the deposition of the skutterudites from stoichiometric targets. Above this temperature the film is depleted of antimony due to its high vapor pressure eventually reaching a composition where the skutterudite structure is no longer stable. However, when films are grown from antimony-rich targets the substrate temperature can be increased to at least 350°C while maintaining the skutterudite phase. In addition, adhesion properties of the films are explored in terms of the growth mode and substrate interaction. Finally, preliminary room temperature electrical and thermal measurements are reported.

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