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.

Fabrication and Material Analysis of Zinc Oxide Nanorods Grown on Gallium Nitride Substrate

2016 ◽  
Vol 19 (4) ◽  
pp. 181-183 ◽  
Author(s):  
Tzu-Yi Yu ◽  
Yi Cian Chen ◽  
Wang Ting Chiu ◽  
Yang Luo ◽  
Sheng Shin Wang ◽  
...  
Keyword(s):  
Au Nanoparticles ◽  
Zno Nanorods ◽  
Nano Particles ◽  
Zinc Oxide Nanorods ◽  
X Ray Diffraction ◽  
Thermal Methods ◽  
X Ray ◽  
Oxide Nanorods ◽  
Different Temperatures ◽  
Multiple Material

In this study, we address process how the ZnO nanorods were deposited on GaN substrates with spin-coating by using the hydro-thermal methods. After ZnO was spin coated, the samples were annealed with different temperatures to incorporate with Au nano particles. Multiple material analyses, such as the field emission scanning electron microscopy (FESEM), the energy dispersive X-ray spectroscopy (EDX) and the X-ray diffraction (XRD) analyses were carried out to characterize the Au nanoparticles/ZnO nanorods/GaN nanocomposites.

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.

Extraction of Biological Apatite from Cow Bone at Different Calcination Temperatures: A Comparative Study

2019 ◽  
Vol 796 ◽  
pp. 46-52
Author(s):  
Nazia Bano ◽  
Sharifah Adzila ◽  
Suzi Salwah Jikan ◽  
Hatijah Basri ◽  
Nanthini Kanasan
Keyword(s):  
Thermally Stable ◽  
Hexagonal Crystal Structure ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
X Ray ◽  
Calcination Temperatures ◽  
Biological Apatite ◽  
Different Temperatures ◽  
Cow Bone ◽  
Natural Hydroxyapatite

The purpose of this study is to extract natural hydroxyapatite (HAP) from cow bone. The hydrothermal method followed by calcination treatment at different temperatures is used in this current research. Cow bone has the potential for producing hydroxyapatite, a chief component present in bone and teeth of vertebrates. HAP is an excellent material used in bone restoration and tissue regeneration. Characterizations of the cow bone natural HAP powder were done by X-ray diffraction (XRD) and Thermogravimetric analysis (TGA). TGA data revealed that biological apatite is thermally stable at 1100°C. XRD data showed that the extracted HAP is, highly crystalline and hexagonal crystal structure having a crystallite size in the range of 10-83 nm. The extracted HAP material is found to be thermally stable up to 1300°C.

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.

scholarly journals Effects of Calcination Temperatures on The Catalytic Activities of Alumina Supported Cobalt and Chromium Catalysts

2019 ◽  
Vol 14 (3) ◽  
pp. 654
Author(s):  
Mardwita Mardwita ◽  
Eka Sri Yusmartini ◽  
Nidya Wisudawati
Keyword(s):  
Metal Particle ◽  
Strong Support ◽  
High Dispersion ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Calcination Temperatures ◽  
Transmission Electron ◽  
Different Temperatures

Catalysts properties are important for catalytic reactions. The interaction between support and metal in a catalyst is resulted from catalyst preparation. In this study, gamma-alumina (Al2O3) supported cobalt (Co) and chromium (Cr) catalysts were prepared by impregnation method and calcined at two different temperatures, they are 400 °C for 4 hours and 800 °C for 4 hours. The resulted catalysts contained 10 wt.% of metal and denoted as Co/Al2O3(400), Co/Al2O33(800), Cr/Al2O3(400), and Cr/Al2O3(800) catalysts. The surface and state of the catalysts were examined by using x-ray diffraction (XRD), x-ray photoelectron spectrometer (XPS) and transmission electron microscopy (TEM). The XRD result reveals that strong interaction between Co and Al2O3 due to a formation of higher cobalt oxide. The XRD result further indicates aggregation and strong support metal interaction between Co and Al2O3 during calcination. On the other hand, TEM result showed that large Co particle was observed on Al2O3. The Cr/Al2O3 catalysts were characterized by using XPS. The XPS results showed that Cr/Al2O3(800) catalyst was dominated by Cr6+ species at binding energy 579.04 eV, indicating high dispersion of Cr on Al2O3. Moreover, Cr metal particle was not observed on XRD and TEM image. All the characterization results provide information that the impregnated metal on Al2O3 showed different properties. Co metal particle tends to be more oxidized and formed large particle, however it was not observed on Cr metal particle. Copyright © 2019 BCREC Group. All rights reserved 

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.

A New Polyethylene Corrosion Protecting Coating with Ion Selectivity

2011 ◽  
Vol 314-316 ◽  
pp. 273-278
Author(s):  
Yu Hua Dong ◽  
Ke Ren ◽  
Qiong Zhou
Keyword(s):  
Ion Selectivity ◽  
Nano Particles ◽  
Ammonium Bromide ◽  
Linear Low Density Polyethylene ◽  
X Ray Diffraction ◽  
Sulfosalicylic Acid ◽  
X Ray ◽  
Chemically Modified ◽  
Before And After ◽  
Industrial Standards

Linear low density polyethylene (LLDPE) was chemically modified with grafting maleic anhydride (MAH) monomer on its backbone by melting blending. Nano-particles SiO2 was modified by cationic surfactant hexadecyl trimethyl ammonium bromide (CTAB) and anionic surfactant sulfosalicylic acid (SSA) and added to PE coating respectively. Measurement of membrane potential showed that the coating containing modified SiO2 nano-particles had characteristic of ion selectivity. The properties of the different coatings were investigated according to relative industrial standards. Experimental results indicated that PE coating with ion selectivity had better performances, such as adhesion strength, cathodic disbonding and anti-corrosion, than those of coating without ion selectivity. Crystal structure of the coatings before and after alkali corrosion was characterized by Fourier transform infrared spectra (FTIR) and X-ray diffraction (XRD). Structure of the coating without ion selectivity was damaged by NaOH alkali solution, causing mechanical properties being decreased. And the structure of the ion selective coatings was not affected.

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.

scholarly journals Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Durga Sankar Vavilapalli ◽  
Ambrose A. Melvin ◽  
F. Bellarmine ◽  
Ramanjaneyulu Mannam ◽  
Srihari Velaga ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
First Principle ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Principle Calculations ◽  
Photodegradation Efficiency

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.

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