OPTICAL AND STRUCTURAL PROPERTIES OF Ag NANOPARTICLES Eu OXIDE FILMS

2008 ◽  
Vol 07 (06) ◽  
pp. 339-344 ◽  
Author(s):  
A. A. DAKHEL
Keyword(s):  
Lattice Parameter ◽  
Europium Oxide ◽  
Silicon Substrates ◽  
Ag Nanoparticle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nanoparticle Radius ◽  
Different Temperatures ◽  
Bcc Structure ◽  
The Eu

Silver-incorporated europium oxide thin films have been prepared by the successive evaporation method on quartz and silicon substrates. The silver concentration was 2.5% and 8.9% respectively, as measured by X-ray fluorescence. X-ray diffraction revealed that the Eu oxide of these samples remained amorphous after preannealing at 450°C; however, it crystallized in bcc structure at 800°C. The lattice parameter of the crystallized Eu oxide was larger than that of the bulk, due to the adsorption of Ag + ions, which have a higher ionic radius. The optical absorption of the samples manifested the surface plasmon resonance (SPR) phenomenon, which varied with the Ag content and preannealings of the samples at different temperatures. The Ag nanoparticle radius was estimated with the Mie classical theory by using the SPR data analysis.

scholarly journals Photocatalytic Activity and Optical Properties of Blue Persistent Phosphors under UV and Solar Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
C. R. García ◽  
L. A. Diaz-Torres ◽  
J. Oliva ◽  
M. T. Romero ◽  
P. Salas
Keyword(s):  
Photocatalytic Activity ◽  
Annealing Temperature ◽  
Uv Light ◽  
Solar Irradiation ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Water Cleaning ◽  
Different Temperatures ◽  
The Eu

Blue phosphorescent strontium aluminosilicate powders were prepared by combustion synthesis route and a postannealing treatments at different temperatures. X-ray diffraction analysis showed that phosphors are composed of two main hexagonal phases: SrAl2O4and Sr3Al32O51. The morphology of the phosphors changed from micrograins (1000°C) to a mixture of bars and hexagons (1200°C) and finally to only hexagons (1300°C) as the annealing temperature is increased. Photoluminescence spectra showed a strong blue-green phosphorescent emission centered atλem=455 nm, which is associated with4f65d1→4f6  (8S7/2)transition of the Eu2+. The sample annealed at 1200°C presents the highest luminance value (40 Cd/m2) with CIE coordinates (0.1589, 0.1972). Also, the photocatalytic degradation of methylene blue (MB) under UV light (at 365 nm) was monitored. Samples annealed at 1000°C and 1300°C presented the highest percentage of degradation (32% and 38.5%, resp.) after 360 min. In the case of photocatalytic activity under solar irradiation, the samples annealed at 1000°C, 1150°C, and 1200°C produced total degradation of MB after only 300 min. Hence, the results obtained with solar photocatalysis suggest that our powders could be useful for water cleaning in water treatment plants.

Hydrogenation Properties of Mg-Co and Its Related Alloys

2005 ◽  
Vol 475-479 ◽  
pp. 2453-2456
Author(s):  
Y. Zhang ◽  
Y. Tsushio ◽  
Hirotoshi Enoki ◽  
Etsuo Akiba
Keyword(s):  
Binary Alloys ◽  
Lattice Parameter ◽  
Ternary Alloys ◽  
Body Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Co Concentration ◽  
Bcc Structure ◽  
Co Alloys

Novel Mg-Co binary alloys with BCC (body-centered cubic) structure have been successfully synthesized by means of mechanical alloying technique. The formation of BCC structure was confirmed by X-ray diffraction and transmission electron microscopy. Mg-Co alloys were found in the range of Co concentration between 37 and 80 atomic %. All the Mg-Co alloys synthesized absorbed hydrogen below 373K. The maximum hydrogen capacity of these alloys reaches 2.7 mass %. However, desorption of hydrogen at 373 K has not been observed yet. Mg- Co-X (X = B and Ni) ternary alloys with BCC structure have also been synthesized. The lattice parameter of both alloys is lower than that of Mg-Co binary alloys, meanwhile the maximum hydrogen content of both alloys also decreased.

Growth of ZnO Nanostructures at Different Temperatures without Catalyst by Wet Thermal Oxidation Process

2012 ◽  
Vol 620 ◽  
pp. 132-136 ◽  
Author(s):  
Hind I. Abdulgafour ◽  
Yushamdan Yusof ◽  
F.K. Yam ◽  
Hassan Zainuriah
Keyword(s):  
Oxidation Process ◽  
Zinc Powder ◽  
Silicon Substrates ◽  
Zno Nanostructures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Wide Range ◽  
Different Temperatures ◽  
Evaporation Technique

In this study, an efficient method to achieve a wide range of high-quality zinc oxide (ZnO) nanostructures through zinc powder evaporation at different temperatures is developed. ZnO nanostructures could be synthesized on n-type silicon substrates by a simple thermal evaporation technique without a catalyst at 600°C, 700°C, 800°C, and 900°C. Samples are annealed in wet oxygen and ambient argon gases. Surface morphology, crystallinity, and optical properties of the ZnO nanostructures are examined by scanning electron microscopy and transmission electron microscope measurements, X-ray diffraction, and photoluminescence measurement.

scholarly journals Electrical and optical properties of spin-coated SnO2 nanofilms

2014 ◽  
Vol 32 (4) ◽  
pp. 729-736 ◽  
Author(s):  
Weronika Izydorczyk ◽  
Krzysztof Waczyński ◽  
Jacek Izydorczyk ◽  
Paweł Karasiński ◽  
Janusz Mazurkiewicz ◽  
...  
Keyword(s):  
Thin Films ◽  
Precursor Solution ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Electrical And Optical Properties ◽  
X Ray ◽  
Different Temperatures ◽  
Sno2 Thin Films ◽  
Deposited Films ◽  
Nanocrystalline Thin Films

AbstractSnO2 nanocrystalline thin films have been deposited on oxidized silicon substrates by spin-coating from a precursor solution, followed by slow thermal annealing in oxygen atmosphere at different temperatures (500 to 900 °C). The precursor solution consisted of 1.0 to 2.0 M SnCl4·5H2O in isopropanol. It was shown that the concentration of the precursor solution, annealing temperature and heating rate had a significant effect on the structural, optical and electrical properties of the studied thin films. The topography of SnO2 thin films was examined by scanning electron microscopy (SEM). Furthermore, as-deposited films were characterized by X-ray diffraction (XRD), UV-Vis and impedance spectroscopy.

Stoichiometry and Alloying Effects on the Phase Stability and Mechanical Properties of TiCr2-Base Laves Phase Alloys

1994 ◽  
Vol 364 ◽  
Author(s):  
Katherine C. Chen ◽  
Samuel M. Allen ◽  
James D. Livingston
Keyword(s):  
Fracture Toughness ◽  
Single Phase ◽  
Lattice Parameter ◽  
Phase Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Composition Effects ◽  
Different Temperatures ◽  
Diffraction Lattice ◽  
Alloying Effects

AbstractTi-Cr alloys near the TiCr2 composition have been studied to determine the single-phase Laves field and the associated defects accompanying off-stoichiometry. A combination of metallography, x-ray diffraction, lattice parameter measurements, density measurements and electron microprobe analysis have been used to establish a narrow single-phase region extending towards Ti-rich compositions. All three Laves crystal structures (C14, C36 and C15) were found to exist at different temperatures. Hardness and fracture toughness values determined by Vickers microindentation were studied as a function of alloy composition. Effects of adding Fe, Nb, Mo, and V to TiCr2 on lattice parameter, crystal structure, hardness and fracture toughness are reported.

EPR Study of CeO2 Nano Particles

2022 ◽  
Vol 1048 ◽  
pp. 130-138
Author(s):  
Dinesh Uthra ◽  
M.P. Sharma
Keyword(s):  
Continuous Wave ◽  
Lattice Parameter ◽  
Nano Particles ◽  
Intensity Difference ◽  
Nitrate Hexahydrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcination Temperatures ◽  
Different Temperatures ◽  
Calcined Temperature

In this paper, we have studied the EPR spectra, X-ray diffraction and Raman Analysis, Microstructures-morphology of the Ceria NPs calcined at different temperatures of 700 °C, 850 °C ,these materials have been synthesized by Co precipitation (CPT) method by using Cerium tri-nitrate hexahydrate and potassium carbonate solutions. Then synthesized precipitate was heated at 70 °C for 20 hour. Slow grinding of the precipitate and calcined for 3 hours at different temperatures viz. 700 °C and 850 °C to form fine Cerium oxide powder-Ceria NPs. The EPR measurements were made using continuous wave spectrometer (X-band, Bruker Biospin EMX Plus). The g values were obtained by using diphynelpirichylhydrageyl (DPPH-C18H12N5O6) sample and got g value is around 1.97. This g tensor is decreased when the calcined temperature are increased, EPR parameters are also changed as the calcined temperature increases. When the calcined temperature is increased from 700 °C to 850 °C, a doublet separated, intensity increased. The X-Ray diffraction pattern shows the nature of the Ceria NPs crystal, with a cubic structure and got the lattice parameters 5.392 Å for samples calcined at temperature of 700 °C and 5.357 Å at 850 °C which shows decreasing trend in lattice parameter with calcination temperature. The intensity of Raman peaks is also shifted upwards with a rise in temperature. This intensity difference could be because of the rise in vibrational amplitudes of the closest neighboring bonds because of the increase in particle size 11.3± 1.0 to 15.6± 1.0 nm at calcination temperatures of 700 °C and 850 °C and the Raman peak of peak I, 461 cm-1 and peak II, 463 cm-1 respectively. Other peaks were not observed in this Raman pattern. The EDS analysis confirms the presence of the Ce and O atoms in the synthesized samples. Spherical shapes and homogeneously distributed Ceria NPs and a rather tendency for agglomeration were confirmed.

Synthesis of iron nanocomposite reinforced by TiC particles via mechanical activation from ilmenite concentrate and carbon black

2016 ◽  
Vol 23 (4) ◽  
pp. 381-388 ◽  
Author(s):  
Alireza Firouzbakht ◽  
Mansour Razavi ◽  
Mohammad Reza Rahimipour
Keyword(s):  
Carbon Black ◽  
Raw Materials ◽  
Lattice Parameter ◽  
Synthesis Temperature ◽  
X Ray Diffraction ◽  
Standard Size ◽  
X Ray ◽  
Ilmenite Concentrate ◽  
Different Temperatures ◽  
Atmosphere Control

AbstractIn this research, synthesis of Fe-TiC nanocomposites from activated ilmenite concentrate and carbon black was investigated. Ilmenite and carbon black as raw materials were milled in a planetary ball mill and sampled after different milling times. The activated powder was heat treated at different temperatures in an atmosphere control tube furnace and analyzed by X-ray diffraction technique. The X-ray diffraction results showed that increasing the milling time would lower the synthesis temperature of final products. Furthermore, the lattice parameter showed deviation from standard size, and mean grain size was decreased. In contrast, the strain of the system was increased based on the calculations.

Adjust the Content of Nickel in NiZnO Films by Vacuum Anneal

2012 ◽  
Vol 562-564 ◽  
pp. 11-14 ◽  
Author(s):  
Xin Dong ◽  
Jin Wang ◽  
Hui Wang ◽  
Zhi Feng Shi ◽  
Bao Lin Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Lattice Parameter ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Metal Organic ◽  
Dramatic Shift ◽  
Anneal Temperature

NiZnO films were grown on sapphire substrates by metal-organic chemical vapor deposition (MOCVD). Then the films were annealed in vacuum at different temperatures for 1h. The UV emission peak was blue shifted in the photoluminescence (PL) spectra and a dramatic shift of (002) diffraction peak to higher angle was observed in X-ray diffraction (XRD) pattern with the increasing anneal temperature. It showed the band gap and the lattice parameter of NiZnO had been affected by anneal in vacuum. From the X-ray photoelectron spectroscopy (XPS) of the NiZnO film, we can find that the anneal temperature had an important effect on the content of each element in NiZnO quantificationally. In addition, the value of x in NiZnO varied slightly with the anneal temperature increasing. The above phenomena indicated that anneal in vacuum could slightly adjust the percentage of Ni indirectly in NiZnO film and offer a good idea in NiZnO devices facture.

scholarly journals Thickness-dependent piezoelectric behaviour and dielectric properties of lanthanum modified BiFeo3 thin films

2011 ◽  
Vol 5 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Glenda Biasotto ◽  
Francisco Moura ◽  
Cesar Foschini ◽  
Elson Longo ◽  
Jose Varela ◽  
...  
Keyword(s):  
Thin Films ◽  
Lattice Parameter ◽  
Hexagonal Structure ◽  
Piezoelectric Response ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Bifeo3 Thin Films ◽  
Entire Thickness

Bi0.85La0.15FeO3 (BLFO) thin films were deposited on Pt(111)/Ti/SiO2 /Si substrates by the soft chemical method. Films with thicknesses ranging from 140 to 280 nm were grown on platinum coated silicon substrates at 500?C for 2 hours. The X-ray diffraction analysis of BLFO films evidenced a hexagonal structure over the entire thickness range investigated. The grain size of the film changes as the number of the layers increases, indicating thickness dependence. It is found that the piezoelectric response is strongly influenced by the film thickness. It is shown that the properties of BiFeO3 thin films, such as lattice parameter, dielectric permittivity, piezoeletric coefficient etc., are functions of mis?t strains.

scholarly journals A Superhydrophobic, Antibacterial, and Durable Surface of Poplar Wood

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1885
Author(s):  
Xinyu Wu ◽  
Feng Yang ◽  
Jian Gan ◽  
Zhangqian Kong ◽  
Yan Wu
Keyword(s):  
Stearic Acid ◽  
Antibacterial Properties ◽  
Alkali Resistance ◽  
Poplar Wood ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Acid And Alkali Resistance ◽  
The Stability

The silver particles were grown in situ on the surface of wood by the silver mirror method and modified with stearic acid to acquire a surface with superhydrophobic and antibacterial properties. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray energy spectroscopy (XPS) were used to analyze the reaction mechanism of the modification process. Scanning electron microscopy (SEM) and contact angle tests were used to characterize the wettability and surface morphology. A coating with a micro rough structure was successfully constructed by the modification of stearic acid, which imparted superhydrophobicity and antibacterial activity to poplar wood. The stability tests were performed to discuss the stability of its hydrophobic performance. The results showed that it has good mechanical properties, acid and alkali resistance, and UV stability. The durability tests demonstrated that the coating has the function of water resistance and fouling resistance and can maintain the stability of its hydrophobic properties under different temperatures of heat treatment.

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