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.

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 Synthesis of Zirconia Nanoparticles and Their Ameliorative Roles as Additives Concrete Structures

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Masoud Negahdary ◽  
Amir Habibi-Tamijani ◽  
Asadollah Asadi ◽  
Saeid Ayati
Keyword(s):  
Setting Time ◽  
Average Particle Size ◽  
Concrete Structures ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Split Tensile Strength ◽  
Transmission Electron ◽  
Uv Visible ◽  
20 Nm ◽  
Zirconia Nanoparticles

We investigated synthesis of zirconia nanoparticles (Nps) and their ameliorative roles as additives concrete structures. Synthesized Zirconia Nps were studied with X-ray diffraction (XRD), UV-visible spectrophotometer, and transmission electron microscope (TEM). We used standard Portland cement in related experiment Concrete Structures. The experimental or E series (E1–E4) mixtures were prepared with different amounts of ZrO2Nps with an average particle size of 20 nm. The experimental mixtures were prepared 0.125, 0.25, 0.5 and 2.0% ZrO2Nps/cement by weight. The modified cement with ZrO2nanoparticles was studied with split tensile strength, flexural strength and setting time methods. Final results showed that Zirconia Nps could be used for their Ameliorative roles as Additives Concrete Structures.

scholarly journals Green Synthesis of Novel Jasmine Bud-Shaped Copper Nanoparticles

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Malathi Sampath ◽  
Ramya Vijayan ◽  
Ezhilarasu Tamilarasu ◽  
Abiraman Tamilselvan ◽  
Balasubramanian Sengottuvelan
Keyword(s):  
Copper Nanoparticles ◽  
Isonicotinic Acid ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Acid Hydrazide ◽  
Reducing Agent ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Atomic Force ◽  
Transmission Electron

Novel jasmine bud-shaped copper nanoparticles were synthesized by a green chemical reduction method using polyvinylpyrrolidone (PVP) as a capping agent, L-ascorbic acid (AA) as a reducing agent as well as antioxidant agent, isonicotinic acid hydrazide (INH) as a reducing agent, and water as a solvent at 60–70°C (pH-7) in the presence of air. The UV-Vis absorption maximum obtained is 573 nm. The crystal lattice (fcc) structure of Cu Nps was confirmed by X-ray diffraction (XRD). The novel jasmine bud shape was visualized in a transmission electron microscope (TEM). The height of single copper nanobud was 6.41 nm as measured by atomic force microscope (AFM). The average particle size 6.95 nm is obtained by XRD results. Antibacterial activity of the Cu nanobuds was evaluated by testing against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria.

Structural, Microscopy Analysis and Compressive Strength of ZnO–CuO Nanocomposites

2020 ◽  
Vol 12 (2) ◽  
pp. 163-167
Author(s):  
K. Kavitha ◽  
T. Subba Rao ◽  
R. Padma Suvarna ◽  
M. Prasanna Kumar
Keyword(s):  
Compressive Strength ◽  
Sol Gel ◽  
Average Particle Size ◽  
Testing Machine ◽  
Research Area ◽  
Strength Analysis ◽  
Average Particle ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Active Research

Currently, researches on nanocomposites become an active research area due its unique properties. Earlier, many researches are done for synthesizing the multidimensional structures for developing efficient and new Nano devices. In this present work, we synthesized ZnO–CuO nanocomposites using sol–gel method. The obtained nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) analysis and Compressive strength analysis using compressive testing machine (CTM). Herein, the structure and size of the ZnO–CuO nanocomposites were studied using XRD. And the average particle size was found to be 34 nm. The TEM analysis has the evidence of the XRD result. The enhancement in compressive strength of the ZnO–CuO nanocomposites was determined using CTM machine up to 4 wt.%.

Low temperature chemical synthesis of nanocrystalline Pb(Mg1/3Nb2/3)O3 and (1–x)Pb(Mg1/3Nb2/3)O3–xPb(Fe1/2Nb1/2)O3 (x = 0.1, 0.2, and 1) ceramics

2000 ◽  
Vol 15 (11) ◽  
pp. 2273-2275 ◽  
Author(s):  
R. N. Das ◽  
J. C. Ray ◽  
P. Pramanik
Keyword(s):  
Ethylenediaminetetraacetic Acid ◽  
Average Particle Size ◽  
Homogeneous Solution ◽  
Lead Magnesium Niobate ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Precursor Material ◽  
Lead Magnesium ◽  
20 Nm ◽  
Iron Niobate

Nanocrystalline (20 nm) lead magnesium niobate (PMN) powders were prepared via a chemical process. This process involved the addition of aqueous niobium tartrate, lead-ethylenediaminetetraacetic acid, and magnesium-polyvinyl alcohol complex to produce a homogeneous solution. After the complete evaporation of the resulting homogeneous solution, the complexes decomposed and produced a black, fluffy precursor material. The precursor material on calcination up to 850 °C/2 h produced nanocrystalline PMN powders with the corresponding average particle size 20 nm. PMN powders modified with lead iron niobate (PFN) (1 – x)PMN–xPFN (x = 0.1, 0.2, and 1) were also prepared using this route and investigated through x-ray diffraction studies.

TiO2 Nanoparticles Synthesized with Ti(SO4)2 as Precursor via the Hydrothermal Method and their Optical Absorption Properties

2017 ◽  
Vol 727 ◽  
pp. 280-283
Author(s):  
Xiao Ming Fu
Keyword(s):  
Hydrothermal Method ◽  
Ph Value ◽  
Blue Shift ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Absorption Properties ◽  
Tem Analysis ◽  
Visible Absorption ◽  
Transmission Electron ◽  
20 Nm

Anatase TiO2 particles of about 20 nm in the diameter were successfully synthesized with Ti (SO4)2 as titanium source and stronger ammonia water as precipitant at 240°C for 48 h with pH=5 using the hydrothermal method. The samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and ultraviolet-visible absorption spectroscopy (UV-VIS). XRD analysis showed that the phase of the samples was anatase TiO2. TEM analysis confirmed that TiO2 particles of about 50 nm in the diameter were obtained when the pH value was 0.12. With the increasement of the pH value, the size of as-prepared TiO2 particles became remarkably fine. However, with the further increase of the pH value, the size of TiO2 particles was not obvious. TiO2 particles of about 20 nm in the diameter were obtained when the pH value was 5. And UV-VIS results showed that the size of anatase TiO2 nanoparticles, which became small, was propitious to the blue shift of their absorption peak.

DIELECTRIC PROPERTIES OF ULTRAFINE Zn-DOPED CaCu3Ti4O12 CERAMIC

2012 ◽  
Vol 02 (01) ◽  
pp. 1250007 ◽  
Author(s):  
LAXMAN SINGH ◽  
U. S. RAI ◽  
K. D. MANDAL ◽  
MADHU YASHPAL
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Single Phase ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sintered Powder

Ultrafine powder of CaCu2.80Zn0.20Ti4O12 ceramic was prepared using a novel semi-wet method. DTA/TG analysis of dry powder gives pre-information about formation of final product around 800°C. The formation of single phase was confirmed by X-ray diffraction analysis. The average particle size of sintered powder of the ceramic obtained from XRD and Transmission electron microscopy was found 59 nm and 102 nm, respectively. Energy Dispersive X-ray studies confirm the stoichiometry of the synthesized ceramic. Dielectric constant of the ceramic was found to be 2617 at room temperature at 1 kHz.

Frequency dependence and fuel effect on optical properties of nano TiO2-based structures

2016 ◽  
Vol 30 (18) ◽  
pp. 1650247 ◽  
Author(s):  
Mahdi Ghasemifard ◽  
Misagh Ghamari ◽  
Meysam Iziy
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Average Particle Size ◽  
Combustion Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Nano Tio2 ◽  
Transmission Electron ◽  
Auto Combustion ◽  
Xrd Patterns

TiO2-(Ti[Formula: see text]Si[Formula: see text]O2 nanopowders (TS-NPs) with average particle size around 90 nm were successfully synthesized by controlled auto-combustion method by using citric acid/nitric acid (AC:NA) and urea/metal cation (U:MC). The structure of powders was studied based on their X-ray diffraction (XRD) patterns. The XRD of TS-NPs shows that rutile and anatase are the main phases of TS-NPs for AC:NA and U:MC, respectively. Particle size and histogram of nanopowders were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Optical properties of TS-NPs were calculated by Fourier transform infrared spectroscopy (FTIR) and Kramers–Kroning (KK) relation. Plasma frequencies of TS-NPs obtained from energy loss functions depend on fuels as a result of changes in crystal structure, particle size distribution, and morphology.

scholarly journals Magnetic and Structural Studies of CoFe2O4Nanoparticles Suspended in an Organic Liquid

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Branka Babić-Stojić ◽  
Vukoman Jokanović ◽  
Dušan Milivojević ◽  
Zvonko Jagličić ◽  
Darko Makovec ◽  
...  
Keyword(s):  
Room Temperature ◽  
Bulk Material ◽  
Organic Liquid ◽  
Average Particle Size ◽  
Hydrodynamic Diameter ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Ferrite Nanoparticle ◽  
Nanoparticle System

We present a study of magnetic and structural properties of CoFe2O4nanoparticles suspended in an organic liquid. Transmission electron microscopy shows that the nanoparticles have a narrow size distribution of average particle size 5.9 ± 1.0 nm. X-ray diffraction shows that the particles are of cubic spinel crystal structure. Dynamic light scattering measurements reveal the existence of an organic shell around the CoFe2O4nanoparticles with an average hydrodynamic diameter of 14.4 nm. Coercive magnetic field atT=5 K is found to be 11.8 kOe. Disappearance of the coercive field and remanent magnetization at about 170 K suggests that the CoFe2O4nanoparticles are superparamagnetic at higher temperatures which is confirmed by the room temperature Mössbauer spectrum analysis. Saturation magnetization of the nanoparticles of 80.8 emu/g(CoFe2O4) at 5 K reaches the value detected in the bulk material and remains very high also at room temperature. The cobalt ferrite nanoparticle system synthesized in this work exhibits magnetic properties which are very suitable for various biomedical applications.

scholarly journals Synthesis and characterization of ZnTe nanoparticles

2016 ◽  
Vol 17 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Sujan Dhungana ◽  
Bhoj Raj Paudel ◽  
Surendra K. Gautam
Keyword(s):  
Particle Size ◽  
Field Effect Transistors ◽  
Average Particle Size ◽  
Precursor Solution ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Zinc Compounds ◽  
Transmission Electron

In this work, we report the ZnTe semiconductor nanoparticles (NPs) prepared by aqueous chemical precipitation method using the tellurium precursor solution with different zinc compounds. Three batches of ZnTe NPs were synthesized to study the effect of dilution on the size and phase purity of ZnTe. The influence of source compounds and concentrations of the size and structure of NPs were studied. ZnTe NPs have great applications as field-effect transistors and photodetectors. The existing controversy regarding the crystalline structure of ZnTe NPs, whether it is cubic or hexagonal, has been resolved using X-ray Diffraction (XRD) data. The ZnTe NPs possess cubic structure, which is also confirmed by Electron Diffraction (ED) pattern. The average particle size determined from XRD data with the help of Debye-Scherrer equation is about 6 nm. The particle size can be further verified by Transmission Electron Microscopy (TEM) studies.  

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