Effect of Rare Earth Doped Elements and Characterization of LaF3:Ln3+ (Ln3+= Ce3+, Pr3+, Nd3+) Nanocrystals

2012 ◽  
Vol 585 ◽  
pp. 174-178 ◽  
Author(s):  
S.G. Gaurkhede ◽  
M.M. Khandpekar ◽  
S.P. Pati ◽  
A.T. Singh
Keyword(s):  
Rare Earth ◽  
Second Harmonic ◽  
Average Particle Size ◽  
Potassium Dihydrogen Phosphate ◽  
Xrd Analysis ◽  
Dihydrogen Phosphate ◽  
Average Particle ◽  
Tem Analysis ◽  
20 Nm

Abstract. LaF3 nanocrystals doped with lanthanides like Ce3+, Pr3+ and Nd3+ have been prepared using microwave technique. These synthesized crystals have been characterized by X-ray powder diffraction. Well dispersed, elongated, nanorods of hexagonal geometry (approximately 20nm in size) have been found in TEM analysis. The average particle size estimated from XRD analysis is about 20 nm and is in close agreement with the TEM results. Four characteristic peaks one at 3434 cm-1 (broad) and other at 2924, 2853, 1632 cm-1(sharp) have been observed in the FTIR spectra. Intense Blue colour (458 nm) emission has been recorded when crystals are excited with photons of wavelength 254 nm. Non Linear Optical (NLO) properties of the synthesized nanocrystals have been studied. It has been found that second harmonic generation (SHG) efficiency of the prepared samples containing rare earth elements is less than pure Potassium dihydrogen phosphate (KDP) crystals.

Blue Fluorescence in Doped LaF3 Nanocrystals Synthesized by Microwave Technique

2012 ◽  
Vol 584 ◽  
pp. 219-223
Author(s):  
S.G. Gaurkhede ◽  
M.M. Khandpekar ◽  
S.P. Pati ◽  
A.T. Singh
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Hexagonal Phase ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Blue Fluorescence ◽  
Tem Analysis ◽  
Selected Area Electron Diffraction ◽  
20 Nm

Hexagonal-phase LaF3: Ce3+, Pr3+, and Sm3+ doped (LCPS) nano-crystals have been synthesized by keeping same molarities of rare earth elements using aqueous route. The samples have been synthesized in conventional microwave on low power range in about an hour’s time. The phase formation has been verified by powder X-ray diffraction (XRD).Hexagonal geometry of the LCPS nano-crystals has been observed with an average particle size of 20 nm by TEM analysis. The JCPDS Card No. (32-0483) and selected area electron diffraction (SAED) pattern has been used for identification of crystal structure. The UV- VIS spectra indicated band gap of 5.00eV. The FTIR spectrums have been used for assignment of fundamental vibrations. Blue fluorescence observed with exciting wavelengths of 254 nm respectively. The presence of rare-earth elements in LCPS nano-crystals have been verified by the EDAX spectra.

scholarly journals Characterization of Silver Nanoparticles Synthesized using Chemical Method and its Antibacterial Property

2020 ◽  
Vol 10 (6) ◽  
pp. 7257-7264
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Silver Nanoparticles ◽  
Bacillus Subtilis ◽  
Average Particle Size ◽  
Chemical Properties ◽  
Xrd Analysis ◽  
Solid Particles ◽  
Average Particle ◽  
Face Centered Cubic ◽  
Tem Analysis

Metal nanoparticles are gaining importance nowadays in nanoscience. The nanoparticle had better physical and chemical properties compared with solid particles due to their large surface area. The silver nanoparticles are employed mostly in medical and electrical applications having outstanding conductivity and antimicrobial activity. In the present investigation, NaBH4 and ethanol were used as a reductant and stabilizer agent from silver nitrate salt as a precursor. The silver nanoparticles obtained were characterized using Fourier-transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) to determine their morphology and size. In XRD analysis, the average particle size was found to be 18.31 nm. The TEM analysis shows crystalline morphology with a face-centered cubic structure. The antibacterial activity was tested against two bacterial cultures, namely Bacillus subtilis and Pseudomonas aeruginosa. The inhibition zones of 19mm and 17mm were observed against Bacillus subtilis and Pseudomonas aeruginosa, respectively.

scholarly journals Synthesis and Characterization of )CeO(x-) CuO(1-x Nanocomposite by Simple Aqueous Route for Solar Cell Application

2021 ◽  
Author(s):  
Wafaa M. Salih ◽  
Ahmed Mahdi Rheima ◽  
Haider A. Kadhum
Keyword(s):  
Solar Cell ◽  
Average Particle Size ◽  
Average Particle ◽  
One Pot ◽  
Solar Cell Application ◽  
Molar Ratios ◽  
Increase With Increase ◽  
Efficiency Increase ◽  
20 Nm

Abstract This work concludes the synthesis of CeO-CuO nanocomposite by one-pot preparation method using three different molar ratios. The resulted nanocomposite was characterized using UV-Vis, XRD, SEM, EDX and TEM and the results show that this nanocomposite was found as spherical-like nanoparticles with high purity and the average particle size is in the range of 10-20 nm.. Furthermore, this nanocomposite was used in the solar cell application as photo anode and the results showed that the efficiency increase with increase of (x) content in the (CuO)x–(CeO2)1-x.

scholarly journals A Study on Synthesis and Characterization of Dy-Doped La0.6Sr0.4Co0.2Fe0.8O3−δ via the Coprecipitation Method

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Negin Mohammadi ◽  
Zahra Khakpour ◽  
Amir Maghsoudipour ◽  
Aida Faeghinia
Keyword(s):  
Phase Formation ◽  
Perovskite Phase ◽  
Average Particle Size ◽  
Xrd Analysis ◽  
Coprecipitation Method ◽  
Synthesis Process ◽  
Average Particle ◽  
Powder Morphology ◽  
Before And After

The perovskite Lanthanum Strontium Cobalt Ferrite (LSCF) is investigated as the cathode material used in intermediate-temperature solid oxide fuel cells (IT-SOFCs). In the present study, La0.6−xDyxSr0.4Co0.2Fe0.8O3−δ (x = 0, 0.3, 0.6) was synthesized through the coprecipitation method. The obtained precipitate was calcined at 500, 700, 900, and 1000°С. Phase characterization of the synthesized LSCF and LDySCF powder before and after heat treatment at 700°С was carried out by X-ray diffraction (XRD) analysis. XRD patterns revealed that the perovskite phase was obtained at 700°С in all calcined samples. Chemical bond study to investigate the synthesis process was conducted using the Fourier transform infrared spectroscopy technique. Thermal analysis of DTA and TG has been utilized to investigate how the calcination temperature affects the perovskite phase formation. According to the STA results, the perovskite phase formation started at 551°С and completed at 700°С. The density values of synthesized powders were 6.10, 6.11, and 6.37 g·cm−3for the undoped and doped samples calcined at 700°С. Powder morphology was studied by field emission scanning electron microscopy (FE-SEM). The micrographs showed the spherical-shaped particles with the average particle size of 24–131 nm.

Investigation on the Structure and Luminescence Performance of Tb-Doped ZnO Nanocrystals Prepared by Direct Precipitation

2014 ◽  
Vol 900 ◽  
pp. 187-190
Author(s):  
Zong Hu Xiao ◽  
Wei Zhong ◽  
Kang Ping Xu ◽  
Yong Huang ◽  
Shui Gen Li ◽  
...  
Keyword(s):  
Average Particle Size ◽  
Green Emission ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Zno Nanocrystals ◽  
Direct Precipitation ◽  
Transmission Electron ◽  
Diffraction Peaks ◽  
20 Nm

Terbium-doped zinc oxide (ZnO:Tb) nanocrystals were prepared by a direct reactive precipitation progress. Incorporation of terbium in ZnO nanocrystals had been proved by X-ray diffraction (XRD), transmission electron microscope (TEM) and fluorescence spectrophotometer. XRD investigations confirm that the samples of ZnO:Tb nanocrystals with a hexagonal wurtzite crystalline structure don’t exist the diffraction peaks of the compounds of terbium. The results of TEM analysis show that the as-prepared samples with an average particle size less than 20 nm were obtained. The photoluminescence (PL) spectra suggest that there is no luminescence peaks corresponding to the terbium compounds in ZnO:Tb samples; the green emission intensity gradually decreases with the increase of the Tb-doped concentration in ZnO matrix. A core-shell model of rare earth (RE) passivated ZnO is proposed, which the passivation layer existing on the ZnO surface, can generate a barrier to impede the formation of oxygen vacancy, corresponding to the green emission.

scholarly journals Biosynthesized gold nanoparticles supported on magnetic chitosan matrix as catalyst for reduction of 4-nitrophenol

2019 ◽  
Vol 15 (3) ◽  
pp. 451-455
Author(s):  
Norfazreen Saffee ◽  
Mustaffa Shamsuddin ◽  
Khairil Juhanni Abd Karim
Keyword(s):  
Gold Nanoparticles ◽  
Analytical Data ◽  
Average Particle Size ◽  
Xrd Analysis ◽  
Average Particle ◽  
Complexation Reaction ◽  
Bending Vibration ◽  
Tem Analysis ◽  
Magnetic Chitosan ◽  
Jcpds File

The design and environmentally-safe synthesis of magnetically recoverable solid-supported metal nanoparticles with remarkable stability and catalytic performance has significant industrial importance. In the present study, we have developed an inexpensive bioinspired approach for assembling gold nanoparticles (AuNPs) in magnetic chitosan network under green, mild and scalable condition. AuNPs were well loaded on the surface of the magnetic support due to the presence of hydroxyl (-OH) and amino (-NH2) groups in chitosan molecules that provided the driving force for the complexation reaction with the Au(III) ions. Reduction of the Au(III) to Au(0) is achieved by using Melicope ptelefolia aqueous leaf extract. The synthesized magnetic chitosan supported biosynthesized Au nanocatalyst was characterized using Fourier Transform Infrared (FT-IR), Carbon, Hydrogen and Nitrogen (CHN), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD) and Atomic Absorption Spectroscopy (AAS) analyses. FTIR spectrum of magnetic chitosan shows peaks at 1570 cm-1 indicative of N-H bending vibration and at 577 cm-1 which designates the Fe-O bond. CHN analytical data further supported the coating of chitosan onto the magnetite. TEM analysis shows an amorphous layer around the magnetite core which supported the coating of chitosan on the magnetite surface and the average particle size of AuNPs calculated was 7.34 ± 2.19 nm. XRD analysis shows six characteristics peaks for magnetite corresponding to lattice planes (220), (311), (400), (422), (511) and (440) in both the magnetite and magnetic chitosan samples (JCPDS file, PDF No. 65-3107). Meanwhile, XRD analysis of catalyst shows characteristic peaks of AuNPs at 2q (38.21°, 44.38°, 62.2°, 77.32° and 80.76°) are corresponding to (111), (200), (220), (311) and (222) lattice plane (JCPDS file, PDF No.04-0784). AAS analysis shows the loading of AuNPs as 5.4%. The rate constant achieved for the reduction of 4-nitrophenol to 4-aminophenol in the presence of hydrazine hydrate using 10 mg of catalyst is 0.0046 s-1. The magnetic chitosan supported AuNPs is effective as catalyst for the reduction of 4-nitrophenol.

Synthesis and Characterization of Bimetallic Fe/Co Nanocatalyst on CNTs for Fischer-Tropsch Reaction

2012 ◽  
Vol 16 ◽  
pp. 9-14 ◽  
Author(s):  
Sardar Ali ◽  
Noor Asmawati Mohd Zabidi ◽  
Duvvuri Subbarao
Keyword(s):  
Particle Size ◽  
Physicochemical Properties ◽  
Average Particle Size ◽  
Xrd Analysis ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Impregnation Method ◽  
Fischer Tropsch ◽  
Temperature Programmed

Cobalt and iron are common catalysts used in the Fischer-Tropsch (FT) reaction. This paper presents the synthesis and characterization of monometallic and bimetallic cobalt and iron nanoparticles supported on carbon nanotubes (CNTs). The CNTs-supported nanocatalysts were synthesized by a wet impregnation method at various ratios of Fe:Co. The physicochemical properties of the samples were analyzed by H2-temperature programmed reduction (TPR), CO and H2-chemisorption analyses, transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis. The effects of incorporation of Fe into Co on the physicochemical properties of Co/CNTs in terms of degree of reduction, CO and H2 chemisorptions and morphologies were investigated. TEM showed that metal nanoparticles were well dispersed on the external surface and inside the CNTs. For monometallic Co/CNTs and Fe/CNTs, the average metal particle size was 5±1 nm and 6±1 nm, respectively. For the bimetallic 70Co30Fe/CNTs nanocatalysts, the average particle size was found to be 4±1 nm. Metal particles attached to the outer walls were bigger than the ones inside the CNTs. H2-TPR analysis of Co/CNTs indicated two temperature regions at 330°C (low temperature) and 491°C (high temperature). The incorporation of iron into cobalt nanocatalysts of up to 30 % of the total metal loading enhanced the catalyst’s H2 and CO chemisorptions capacities and reducibility.

scholarly journals Growth and characterization of hexamethylenetetramine crystals grown from solution

2014 ◽  
Vol 32 (2) ◽  
pp. 164-170 ◽  
Author(s):  
B. Babu ◽  
J. Chandrasekaran ◽  
S. Balaprabhakaran
Keyword(s):  
Single Crystal ◽  
Second Harmonic ◽  
Potassium Dihydrogen Phosphate ◽  
Optical Transmittance ◽  
Xrd Analysis ◽  
Powder Xrd ◽  
Dihydrogen Phosphate ◽  
Single Crystal Xrd ◽  
Second Harmonic Generation Efficiency ◽  
Different Temperatures

AbstractOrganic nonlinear optical single crystals of hexamethylenetetramine (HMT; 10 × 10 × 5 mm3) were prepared by crystallization from methanol solution. The grown crystals were subjected to various characterization techniques such as single crystal XRD, powder XRD, UV-Vis and electrical studies. Single crystal XRD analysis confirmed the crystalline structure of the grown crystals. Their crystalline nature was also confirmed by powder XRD technique. The optical transmittance property was identified from UV-Vis spectrum. Dielectric measurements were performed as a function of frequency at different temperatures. DC conductivity and photoconductivity studies were also carried out for the crystal. The powder second harmonic generation efficiency (SHG) of the crystal was measured using Nd:YAG laser and the efficiency was found to be two times greater than that of potassium dihydrogen phosphate (KDP).

GROWTH AND CHARACTERIZATION OF NEW NONLINEAR OPTICAL SINGLE CRYSTALS OF 3-AMINOPHENOL ORTHOPHOSPHORIC ACID (3-AMPHPH)

2012 ◽  
Vol 26 (06) ◽  
pp. 1150038
Author(s):  
K. RUSSEL RAJ ◽  
P. MURUGAKOOTHAN
Keyword(s):  
Single Crystals ◽  
Nonlinear Optical ◽  
Orthophosphoric Acid ◽  
Second Harmonic ◽  
Potassium Dihydrogen Phosphate ◽  
Xrd Analysis ◽  
Solution Technique ◽  
Dihydrogen Phosphate ◽  
Cell Parameters ◽  
Water As Solvent

The semi-organic 3-aminophenol-orthophosphoric acid (denoted as 3-amphph) single crystals were grown by slow evaporation solution technique with water as solvent. The resulted crystal has well-defined surface morphology and is transparent and colorless with a size of 29 × 17 × 4 mm3. The powder X-ray diffraction (XRD), NMR spectroscopic technique, UV-vis-NIR, TG/DTA and dielectric analysis are used to characterize the crystals. XRD analysis revealed that the crystal lattice of 3-amphph is orthorhombic having cell parameters a = 4.481(2) Å, b = 9.782(4) Å, c = 18.326(4) Å with non-centrosymmetric space group P 212121. Nonlinear optical studies indicated that the second harmonic generation (SHG) efficiency is 2.22 times that of the standard potassium dihydrogen phosphate (KDP) crystals. Growth mechanism and surface textures of the as-grown single crystals were analyzed by chemical etching analysis.

scholarly journals A study on synthesis and characterization of Dy-dopedLa0.6Sr0.4Co0.2Fe0.8O3-δvia co precipitation method

2020 ◽  
Author(s):  
Negin Mohammadi ◽  
Zahra Khakpour ◽  
Amir Maghsoudipour ◽  
Aida Faeghinia
Keyword(s):  
Phase Formation ◽  
Perovskite Phase ◽  
Average Particle Size ◽  
Xrd Analysis ◽  
Precipitation Method ◽  
Synthesis Process ◽  
Average Particle ◽  
Powder Morphology ◽  
Co Precipitation

Abstract The perovskite Lanthanum Strontium Cobalt Ferrite (LSCF) is investigated as the cathode material used in intermediate temperature solid oxide fuel cells (IT-SOFCs). In the present study, La0.6-xDyxSr0.4Co0.2Fe0.8O3-δ(x= 0, 0.3, 0.6) was synthesized through co precipitation method. The obtained precipitate was calcined at500, 700,900and 1000°С. Phase characterization of synthesized LSCF and LDySCF powder before and after heat treatment at 700°Сwas carried out by X-ray diffraction (XRD) analysis. XRD patterns revealed that the perovskite phase was obtained at 700 °С in all calcined samples. Chemical bond study to investigate synthesis process was done using the Fourier transform infrared spectroscopy technique. Thermalanalysis of DTA and TG has been utilized to investigate how the calcination temperature affects the peroveskite phase formation. According to the STA results, the perovskite phase formation started at 551°Сafterwarditcompleted at 700°С.The density values of synthesized powders were 6.10, 6.11 and 6.37g.cm-3for the undoped and doped samples calcined at 700°С. Powder morphology was studied by Field emission scanning electron microscopy. (FE-SEM) micrographs showed the spherical shaped particles with the average particle size of 24-131nm.

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