Synthesis & PL study of GdPO4:Tb,Eu nanophosphor

Tb3+ and Eu3+ ions co-doped containing monoclinic GdPO4 nanocrystals were successfully obtained by a straightforward combustion method. The crystal structure and optical characteristics were investigated by methods: XRD, photoluminescence spectra (PL). The XRD result indicates the GdPO4:10%Tb, x%Eu had monoclinic phase and the average particle size was about 10 nm. Under excitation wavelength at 394 nm, photoluminescent emission spectra of GdPO4:10%Tb, x%Eu nanopowders show strong characteristic emission of Eu3+ ions and no characteristic emission of Tb3+ ions was found. However, under the excitation of 273 nm or 368 nm, the emission spectra of the samples were shown characteristic emission of Tb3+ ions with 5D4 - 7FJ (J=3-6) transitions and Eu3+ ions with 5D0-7FJ (J=0-4) transitions.

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Strontium Phosphate Composite Designed to Red-Emission at Different Temperatures

Materials ◽

10.3390/ma13204468 ◽

2020 ◽

Vol 13 (20) ◽

pp. 4468

Author(s):

Katarzyna Szyszka ◽

Adam Watras ◽

Rafal J. Wiglusz

Keyword(s):

Average Particle Size ◽

Emission Spectra ◽

Charge Compensation ◽

Treatment Temperature ◽

Ion Concentration ◽

Morphological Properties ◽

Excitation Wavelength ◽

Average Particle ◽

Decay Times ◽

Different Temperatures

Eu3+-doped Sr10(PO4)6(OH)2–Sr3(PO4)2 (SrHAp-TSP) composites were obtained via the microwave-stimulated hydrothermal method and post-heat-treated from 750 to 950 °C. Concentration of the Eu3+ ions was set to be 0.5, 1, 2, 3, 5 mol% in a ratio of the strontium ions molar content. The structural and morphological properties were investigated by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FT-IR) techniques. The average particle size of the studied materials annealed at 750, 850 and 950 °C were counted about 100, 131 and 173 nm, respectively. The luminescence properties depending on the dopant ion concentration, heat-treatment temperature, excitation wavelength and temperature were investigated. In the emission spectra, a broad peak corresponding to the 4f65d1 → 4f7 (8S7/2) emission of Eu2+ ions as well as narrow 4f-4f transitions typical for Eu3+ ions can be observed. The luminescence intensity of the 1 mol% Eu3+:Sr10(PO4)6(OH)2–Sr3(PO4)2 was measured depending on the ambient temperature in the range of 80–550 K. The CIE 1931 (International Commission on Illumination) chromaticity diagram was determined from emission spectra measured in 80, 300 and 550 K. The reduction mechanism of the Eu3+ to the Eu2+ was explained by the charge compensation mechanism based on the Kröger–Vink-notation. The decay times were measured and the Judd–Ofelt (J–O) theory was applied to analyze the observed structural and spectroscopic features.

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Preparation of Barium Strontium Titanate Ceramics via Combustion Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.55-57.185 ◽

2008 ◽

Vol 55-57 ◽

pp. 185-188

Author(s):

Theerachai Bongkarn ◽

C. Wicheanrat

Keyword(s):

Crystal Structure ◽

Perovskite Phase ◽

Average Particle Size ◽

Combustion Method ◽

Cubic Phase ◽

Average Particle ◽

X Ray Diffraction ◽

Pure Perovskite Phase ◽

Average Grain Size ◽

Titanate Ceramics

This study concentrated on the crystal structure and microstructure of [(Ba0.75Sr0.25)TiO3; (BST)] ceramics at different firing temperatures. The BST powders were prepared by a combustion method. (CO(NH2)2) was used as a fuel. Crystallinity of the calcined powders was improved by increasing the calcining temperature, as indicated by the increase in intensity of the X-ray diffraction peak. The pure perovskite phase of BST powders was obtained with a calcinations condition of 1200 oC. The a axis lattice constant of BST calcined powders and sintered ceramics were calculated and it was found that the crystal structure is a cubic phase. The microstructure of BST calcined powders and sintered ceramics were analyzed by a scanning electron microscope (SEM). The SEM result indicated that the average particle size and average grain size increased with the increase of calcinations and sintering temperatures, respectively. The apparent density of the samples was measured by the Archimedes method.

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Microstructure Characterization of Ag Nanoparticles Prepared by Hydrothermal Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.476-478.1138 ◽

2012 ◽

Vol 476-478 ◽

pp. 1138-1141

Author(s):

Zhi Qiang Wei ◽

Qiang Wei ◽

Li Gang Liu ◽

Hua Yang ◽

Xiao Juan Wu

Keyword(s):

Crystal Structure ◽

Particle Size ◽

Hydrothermal Method ◽

Ag Nanoparticles ◽

Average Particle Size ◽

Average Particle ◽

Face Centered Cubic ◽

Selected Area Electron Diffraction ◽

Transmission Electron ◽

Face Centered

Ag nanoparticles were successfully synthesized by hydrothermal method under the polyol system combined with traces of sodium chloride, Silver nitrate(AgNO3) and polyvinylpyrrolidone (PVP) acted as the silver source and dispersant respectively. The samples by this process were characterized via X-ray powder diffraction (XRD), Brunauer–Emmett–Teller (BET) adsorption equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED) to determine the chemical composition, particle size, crystal structure and morphology. The experiment results indicate that the crystal structure of the samples is face centered cubic (FCC) structure as same as the bulk materials, The specific surface area is 24 m2/g, the particle size distribution ranging from10 to 50 nm, with an average particle size about 26 nm obtained by TEM and confirmed by XRD and BET results.

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Influence of Excess Bi2O3 and Na2Co3 on Crystal Structure and Microstructure of Bismuth Sodium Titanate Ceramics

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.474-476.1711 ◽

2011 ◽

Vol 474-476 ◽

pp. 1711-1714 ◽

Cited By ~ 1

Author(s):

Panadda Sittiketkron ◽

Arrak Klinbumrung ◽

Theerachai Bongkarn

Keyword(s):

Crystal Structure ◽

Dielectric Properties ◽

Perovskite Phase ◽

Average Particle Size ◽

Sodium Titanate ◽

Solid State Reaction Method ◽

Lattice Parameter ◽

Rhombohedral Structure ◽

Average Particle ◽

Average Grain Size

This study investigated the influence of excess Bi2O3 and Na2CO3 on the crystal structure, microstructure and dielectric properties of (Bi0.5Na0.5)TiO3 (BNT) ceramics. The BNT ceramics were synthesized using the solid-state reaction method with various excess Bi2O3 and Na2CO3 levels (0, 1, 2, 3 and 4 mol%). The X-ray characterization revealed that all samples had a rhombohedral structure. A pure perovskite phase was obtained in all samples. The lattice parameter a tended to increase with increased excess Bi2O3 and Na2CO3 content in the calcined powders and sintered ceramics. The average particle size increased while, the average grain size tended to decreased with increased of excess Bi2O3 and Na2CO3 content. The depolarization temperature (Td) and the Curie temperature (Tc) were slightly decreased with the increase of excess Bi2O3 and Na2CO3 content. The dielectric properties were related to the density.

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Nanocrystalline α-Fe2O3: A Superparamagnetic Material for w-LED Application and Waste Water Treatment

10.21203/rs.3.rs-327620/v1 ◽

2021 ◽

Author(s):

Mahesh Gaidhane ◽

Deepak Taikar ◽

Pravin Gaidhane ◽

Kalpana Nagde

Keyword(s):

Photocatalytic Activity ◽

Waste Water Treatment ◽

Sol Gel ◽

Average Particle Size ◽

Emission Spectra ◽

Broad Emission Band ◽

Average Particle ◽

X Ray ◽

Prepared Material ◽

Cie Chromaticity

Abstract Nanocrystalline α-Fe2O3 is synthesized by sol-gel technique. The prepared nanomaterial was characterized by X-ray diffraction (XRD), SEM, TEM, Fourier Transform Infrared (FTIR) spectroscopy, Vibrating Sample Magnetometry (VSM) and photoluminescence (PL) techniques. X-ray powder diffraction analysis confirmed the formation of α-Fe2O3. Electron microscopy showed spherical morphologies with an average particle size of 30-40 nm. The magnetic property of the prepared material was studied by VSM at room temperature. VSM study shows superparamagnetic nature of the synthesized nanoparticles. Photoluminescence (PL) emission spectra show intense broad emission band centered at 570 nm with 393 nm excitation indicating its usefulness for w-LED application. The CIE-chromaticity color coordinates of prepared material were calculated. The photocatalytic activity of the α-Fe2O3 nanoparticles was analyzed and the nanopowder exhibited good photocatalytic activity for the removal AO7 from its aqueous solution.

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Preparation of Magnesium-Based Cobalt-Ferrites (Co1−xMgxFe2O4) Nanoparticles by Sol–Gel Auto Combustion Method

International Journal of Nanoscience ◽

10.1142/s0219581x17600122 ◽

2017 ◽

Vol 17 (01n02) ◽

pp. 1760012

Author(s):

S. Gowreesan ◽

A. Ruban Kumar

Keyword(s):

Particle Size ◽

Structural Parameters ◽

Sol Gel ◽

Average Particle Size ◽

Combustion Method ◽

Dielectric Behavior ◽

Powder Xrd ◽

Average Particle ◽

Cobalt Ferrites ◽

Auto Combustion

The scope of the present work is in enhancing the particle size, and dielectric properties of Mg-substituted Cobalt ferrites nanoparticles prepared by sol–gel auto combustion method. The different ratios of Mg-substituted Co Ferrites (Co[Formula: see text]MgxFe2O4([Formula: see text], 0.05, 0.10, 0.15, 0.20 and 0.30)) are calcinated at 850[Formula: see text]C. The synthesized nanoparticles were characterized by powder XRD, FTIR, FE-SEM, EDX techniques and dielectric behavior. The structural parameters were confirmed from powder XRD and the average particle size is obtained from 39 to 67 nm due to the substitution of Mg[Formula: see text] which was calculated by Debye Scherrer’s formula. FE-SEM showed the surface morphology of the different ratio of the sample. The dielectric loss has measured the frequency range of 50[Formula: see text]Hz–5[Formula: see text]MHz. From electrical modulus, conductivity relaxation and thermal activation of charge carriers has been discussed.

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Photoluminescences properties of lanthanum-silver co-doped ZnO nano particles

Modern Electronic Materials ◽

10.3897/j.moem.4.4.35063 ◽

2018 ◽

Vol 4 (4) ◽

pp. 135-141 ◽

Cited By ~ 1

Author(s):

V. Porkalai ◽

B. Sathya ◽

D. Benny Anburaj ◽

G Nedunchezhian ◽

S. Joshua Gnanamuthu ◽

...

Keyword(s):

Zno Nanoparticles ◽

Zinc Acetate Dihydrate ◽

Average Particle Size ◽

Semiconductor Nanoparticles ◽

Nano Particles ◽

Average Particle ◽

Rare Earth Ion ◽

X Ray ◽

Doped Zno ◽

Co Doped

Recently, transition metal (TM) and rare earth ion doped II–VI semiconductor nanoparticles have received much attention because such doping can modify and improve optical properties of II–VI semiconductor nanoparticles by large amount. In this study, undoped, La doped and La+Ag co-doped ZnO nano particles have been successfully synthesized by sol-gel method using the mixture of Zinc acetate dihydrate and ethanol solution. The powders were calcinated at 600 °C for 2 h. The effect of lanthanum and lanthanum-silver incorporation on the structure, morphology, optical and electrical conductivity were examined by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Absorption (EDAX), Fourier transform infrared spectroscopy (FTIR), UV and Photo Luminescence (PL) Characterization. The average particle size of the synthesized ZnO nanoparticles is calculated using the Scherrer formula and is found to be of less than 20 nm. Luminescences properties were found to be enhanced for the La and La+Ag co-doped ZnO nanoparticles.

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Minimum Particle Diameter of the Vanadium/Iron Co-Doped Nano TiO2 Transparent Hydrosol at Room Temperature

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.989-994.611 ◽

2014 ◽

Vol 989-994 ◽

pp. 611-614

Author(s):

Ling Li ◽

Wen Ming Zhang ◽

Hua Yan Zhang ◽

Zi Hao Xu ◽

Sen Wang ◽

...

Keyword(s):

Particle Size ◽

Room Temperature ◽

Raw Materials ◽

Average Particle Size ◽

Particle Diameter ◽

Ferric Nitrate ◽

Average Particle ◽

Hydrolysis Method ◽

Vanadium Iron ◽

Co Doped

Vanadium/iron co-doped nanoTiO2 transparent hydrosol with an average particle size of 3.8 nm was synthesized by a novel complexation-controlled hydrolysis method at room temperature and atmospheric pressure by using TiCl4, ferric nitrate, ammonium metavanadate, etc. as raw materials. The composition, phase structure, particle size, absorbance spectrum, and photocatalytic performance of samples were characterized by XRD, EDS, nanolaser particle size analyzer, and UV-Vis spectrophotometer. The photocatalytic properties of V/Fe doped TiO2 were studied through degrading acid 3R dye, and the results show that when the content of V/Fe was 0.5%, the degradation rate reached more than 96% under irridation for 60 min.

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Preparation and Particle Size Characterization of Cu Nanoparticles Prepared by Anodic Arc Plasma

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.92.163 ◽

2010 ◽

Vol 92 ◽

pp. 163-169

Author(s):

Hong Xia Qiao ◽

Zhi Qiang Wei ◽

Ming Ru Zhou ◽

Zhong Mao He

Keyword(s):

Crystal Structure ◽

Particle Size ◽

Specific Surface ◽

Size Distribution ◽

Surface Area ◽

Specific Surface Area ◽

Average Particle Size ◽

Spherical Shape ◽

Average Particle ◽

Uniform Size

Copper nanoparticles were successfully prepared in large scales by means of anodic arc discharging plasma method in inert atmosphere. The particle size, specific surface area, crystal structure and morphology of the samples were characterized by X-ray diffraction (XRD), BET equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED). The experiment results indicate that the crystal structure of the samples is fcc structure as same as that of the bulk materials. The specific surface area is is 11 m2/g, with the particle size distribution ranging from 30 to 90 nm, the average particle size about 67nm obtained from TEM and confirmed from XRD and BET results. The nanoparticles have uniform size, higher purity, narrow size distribution and spherical shape can be prepared by this convenient and effective method.

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Green Route Synthesis of MgO Nanoparticles Using Murraya Koenigii Leaf Extract: An Efficient Photo Catalyst for Malachite Green

Advanced Science Letters ◽

10.1166/asl.2018.12199 ◽

2018 ◽

Vol 24 (8) ◽

pp. 5801-5804

Author(s):

K. N. Shravana Kumara ◽

H. P Nagaswarupa ◽

K. R. Vishnu Mahesh ◽

M Mylarappa ◽

S. C Prashantha ◽

...

Keyword(s):

Electron Microscopy ◽

Average Particle Size ◽

Diffraction Method ◽

Combustion Method ◽

Average Particle ◽

Murraya Koenigii ◽

Solution Combustion ◽

Efficient Catalyst ◽

Mgo Nanoparticles ◽

Average Size

The objective of this work is mainly focused on green synthesis and characterization of MgO nanoparticles by low temperature solution combustion method. The Murraya koenigii (Curry leaves) was used as a reducing agent (as fuel). The average size and crystallinity of nano MgO particles are analyzed by X-ray Diffraction method (PXRD) and accurate morphology was studied using Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). From XRD, shows that average particle size of MgO is 40 nm. The synthesized MgO particles used as an efficient catalyst shows rapid color removal and reduction in the concentration of dyes.

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