scholarly journals Diverse Nano Dimension of SDS, PEG and CTAB Roofed MgO Nano Powder Synthesized by Co-precipitation Method

2017 ◽  
Vol 7 (3) ◽  
Author(s):  
Rajendran Varadharajan
Keyword(s):  
Band Gap ◽  
Electronic Devices ◽  
Visible Region ◽  
Band Gap Energy ◽  
Precipitation Method ◽  
Cubic Phase ◽  
Xrd Pattern ◽  
Nano Powder ◽  
Different Dimensions ◽  
Co Precipitation

The SDS, PEG and CTAB roofed MgO nano powders were synthesized by co-precipitation method.  The sintered nano powders was shown Fm-3m space group with cubic phase obtained by the XRD pattern. The lattice strain was calculated to be used Williamson-Hall equations (W-H). The formation of Mg-O bond and hydroxyl radicals on the surface were confirmed by the FTIR analyses. The TEM revealed that the morphology of sintered nano powders has three different dimensions (0D, 1D, 2D) with average crystallites size was about ̴ 20-80 nm and length usually 200-500 nm. The UV-DRS spectra show that the ionic surfactants roofed MgO leads to band gap shrinkage. The evaluated optical band gap energy is Eg= 4.10eV, 3.41eV and 3.12eV for SDS, PEG and CTAB-MgO nano powder respectively.  Also extending light absorption towards the visible region due to decrease in crystallite size of surfactants roofed MgO nano powders utilizing for photocatalytic purpose and opto electronic devices.

scholarly journals Synthesis, electrical and magnetic properties of polymer coated magnetic nanoparticles for application in MEMS/NEMS

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Muhammad Arshad Javid ◽  
Muhammad Sajjad ◽  
Saeed Ahmad ◽  
Muhammad Azhar Shahid Khan ◽  
Khalid Nadeem ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Research Work ◽  
Precipitation Method ◽  
Cubic Phase ◽  
Conductivity Measurements ◽  
Xrd Pattern ◽  
Electrical And Magnetic Properties ◽  
Co Precipitation ◽  
Average Size

Abstract In this research work, polymer coated magnetic nanoparticles were prepared by co-precipitation method. The samples were characterized by XRD, SEM, EDS, VSM and two probe DC conductivity measurements. XRD pattern indicated the existence of a sole cubic phase of Fe3O4 with Miller indices (2 2 0), (3 1 1), (5 1 1), (4 4 0). An average size of magnetic nanoparticles was about 22.9 nm and it was reduced to 21.3 nm and 19.4 nm after 1 wt. %. and 2 wt. % coating of PEG-6000, respectively. The morphology and size of the samples were investigated by scanning electron microscope (SEM). EDX spectra confirmed the coating of PEG on magnetic nanoparticles. Magnetic properties were examined by vibrating sample magnetometer (VSM). Saturation magnetization (M s ) decreased as the concentration of PEG increased in the magnetic material. Electrical properties of uncoated and polymer coated Fe3O4 nanoparticles were studied by two-probe conductivity meter. This study concluded that the thermal flow of charge in polymer coated magnetic nanoparticles can be evaluated at micro and nano level.

The Optical Performance of Holmium Oxide Doped Tellurite Glass for Potential Optical Fiber

2021 ◽  
Vol 317 ◽  
pp. 95-99
Author(s):  
Muhammad Noorazlan Abd Azis ◽  
Halimah Mohamed Kamari ◽  
Suriani Abu Bakar ◽  
Azlina Yahya ◽  
Umar Saad Aliyu
Keyword(s):  
Refractive Index ◽  
Band Gap ◽  
Tellurite Glass ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Gap Energy ◽  
Xrd Method ◽  
Nonlinear Pattern

Borotellurite glass had been widely applied in the field of optical communications and devices. In this work, holmium oxides doped borotellurite glass had been successfully fabricated via conventional melt-quenched technique. The structural properties of holmium doped tellurite glass were found using x-ray diffraction (XRD) method. The nonexistence of sharp peaks in XRD pattern shows that the inclusion of holmium tellurite glass leads to the formation long range of disorderness. The optical properties of the glass system such as refractive index and optical band gap energy are investigated using UV-Vis spectrophotometer. The value of refractive index is found in nonlinear trend along with holmium oxides concentration. It is found that the refractive index is more than 2 at 0.01, 0.03 and 0.04 of holmium concentrations. The optical band gap energy was found in similar trend with refractive index which is in nonlinear pattern.

scholarly journals Effect of thickness on the optical properties of Gaas thin films

2013 ◽  
Vol 37 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Chitra Das ◽  
Jahanara Begum ◽  
Tahmina Begum ◽  
Shamima Choudhury
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Refractive Index ◽  
Band Gap ◽  
Optical Band Gap ◽  
Visible Region ◽  
Solar Spectrum ◽  
Band Gap Energy ◽  
Optical Parameters ◽  
Gap Energy

Effect of thickness on the optical and electrical properties of gallium arsenide (GaAs) thin films were studied. The films of different thicknesses were prepared by vacuum evaporation method (~10-4 Pa) on glass substrates at a substrate temperature of 323 K. The film thickness was measured in situ by a frequency shift of quartz crystal. The thicknesses were 250, 300 and 500 nm. Absorption spectrum of this thin film had been recorded using UV-VIS-NIR spectrophotometer in the photon wavelength range of 300 - 2500 nm. The values of some important optical parameters of the studied films (absorption coefficient, optical band gap energy and refractive index; extinction co-efficient and real and imaginary parts of dielectric constant) were determined using these spectra. Transmittance peak was observed in the visible region of the solar spectrum. Here transmittance showed better result when thicknesses were being increased. The optical band gap energy was decreased by the increase of thickness. The refractive index increased by increasing thickness while extinction co-efficient and real and imaginary part of dielectric constant decreased. DOI: http://dx.doi.org/10.3329/jbas.v37i1.15684 Journal of Bangladesh Academy of Sciences, Vol. 37, No. 1, 83-91, 2013

The WS2 dependence on the elasticity and optical band gap energies of swollen PAAm composites

2020 ◽  
Vol 55 (1) ◽  
pp. 71-76
Author(s):  
Gülşen Akın Evingür ◽  
Nafia Alara Sağlam ◽  
Büşra Çimen ◽  
Bengü Özuğur Uysal ◽  
Önder Pekcan
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Polymer Composites ◽  
Optical Band Gap ◽  
Electronic Devices ◽  
Band Gap Energy ◽  
Tungsten Disulfide ◽  
High Electron ◽  
New Generation ◽  
Doped Polymer

New generation nano-filler polymer composites have many applications including biomedical, electronic and maritime related applications because of their mechanical, electronic and optical properties. The properties of composites were investigated as a function of nano-filler content. Among these, tungsten disulfide (WS2) has the potential to be used as a component in electronic devices owing to its high electron mobility and easily tunable optical band gap energy. Tungsten disulfide (WS2)- Polyacrylamide (PAAm) composite was prepared using free radical co-polymerization and wet laboratory methods with WS2 content. Composites were characterized for mechanical and optical properties using an Elasticity Instrument and UV-vis Spectrophotometer, respectively. Elastic modulus was modeled by a statistical thermodynamics model. Tauc’s and Urbach’s Tail model for direct transition were used to model for the optical band gap. In this study, the swelling and WS2 effect on the optical band gap and elasticity of WS2 - PAAm composites were investigated. It was observed that the elasticity presented a reversed behavior of optical band gap energies with respect to WS2 content. For the applications of nano-filler doped polymer composites in flexible electronic devices, WS2 content strongly influences the mechanical and optical properties.

Synthesis and Optical Properties of Annealed Cr Doped ZnS Nanoparticles

2013 ◽  
Vol 678 ◽  
pp. 163-167 ◽  
Author(s):  
D. Amaranatha Reddy ◽  
G. Murali ◽  
N. Madhusudhana Rao ◽  
R.P. Vijayalakshmi ◽  
B.K. Reddy
Keyword(s):  
Optical Properties ◽  
Hexagonal Phase ◽  
Blue Emission ◽  
Precipitation Method ◽  
Cubic Phase ◽  
Structural And Optical Properties ◽  
Zns Nanoparticles ◽  
Blue Emission Peak ◽  
Co Precipitation ◽  
Surface Morphologies

Undoped and Cr doped ZnS nanoparticles with Cr concentrations of 3.0 at.% were prepared by a chemical co-precipitation method for the fist time, using 2-Mercaptoethanol as the capping agent and annealed the synthesized particles at 600°C for 3h in air. The effect of annealing on morphological, structural and optical properties of ZnS and ZnS:Cr have been studied and compared with as prepared samples. EDAX measurements confirmed the presence of Cr in the ZnS lattice and it also confirms the conversion of ZnS into ZnO after annealed at 600 0C/3h. Surface morphologies of all samples were characterized using scanning electron microscopy (SEM). XRD spectra of as synthesized nanoparticles of ZnS and ZnS:Cr exhibited cubic phase. After annealing, the cubic phase is transformed into hexagonal phase. The particle sizes of the ZnS:Cr powders were increased from 5 to 30 nm when the powders were annealed at 600°C. A stable blue emission peak at 445 nm is observed from the as prepared samples (pure ZnS and Cr doped ZnS) but annealed at 600 0C the PL peaked at 500 nm for pure ZnS and Cr doped ZnS nanoparticles exhibited PL peak at 500 nm as well as 654 nm. The emission intensity decreased in annealed particles compared to as synthesized samples.

A Study on Oxygen Storage Capacity of Zirconium-Cerium-Oxide Nanoparticles

2013 ◽  
Vol 685 ◽  
pp. 123-127 ◽  
Author(s):  
Ajin C. Sajeevan ◽  
V. Sajith
Keyword(s):  
Cerium Oxide ◽  
Storage Capacity ◽  
Oxygen Storage Capacity ◽  
Oxygen Storage ◽  
Precipitation Method ◽  
Xrd Pattern ◽  
Harmful Emissions ◽  
Uv Visible ◽  
Co Precipitation

One of the methods for the reduction of harmful emissions from diesel engines such as hydrocarbon, soot and NOx is the use of fuel born catalyst Cerium oxide. The oxygen storage capacity of Cerium oxide can be improved by coating it with metal such as Zirconium. Zr – Ce-O nanoparticles were synthesized by Co-precipitation method in the present work. Dynamic Light scattering, XRD pattern and UV-Visible spectroscopy were used for characterization of the prepared samples. Thermo gravimetric studies were conducted to investigate the thermal decomposition of Zr-Ce-O nanoparticles. The oxygen storage capacity of Zr-Ce-O nanoparticles was analyzed using TPR analysis.

Effect of Surfactant on the Preparation of Nano-powder for Yb Doping Laser Transparent YAG Ceramic

2013 ◽  
Vol 32 (5) ◽  
pp. 511-515 ◽  
Author(s):  
Xiao Guo Cao ◽  
Jia Wang ◽  
Qi Bai Wu ◽  
Hai Yan Zhang
Keyword(s):  
Particle Size ◽  
Polyethylene Glycol ◽  
Average Particle Size ◽  
Ammonium Bicarbonate ◽  
Spherical Particles ◽  
Precipitation Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Nano Powder ◽  
Co Precipitation

AbstractYb:YAG transparent ceramic nano-powder was prepared by chemical co-precipitation method, with ammonium bicarbonate as the precipitant and polyethylene glycol as surfactant. The addition of polyethylene glycol can reduce the agglomeration and particle size of the prepared Yb:YAG powder. The morphology, thermal stability and phase structure of Yb:YAG nano-powder were charactered by scanning electron microscopy (SEM), thermogravimetry and differential thermal analysis (TG-DTA), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy. The results show that well-crystallized nano-powder was obtained by calcining the precursors at 900 °C for 3 h. The average particle size of Yb:YAG powder is about 100–200 nm. When the volume amount of polyethylene glycol is 2.0%, well-dispersed Yb:YAG powder with spherical particles of 100 nm diameter was obtained.

scholarly journals Variation in the material properties by nickel substitution in copper tellurate

2020 ◽  
Author(s):  
Sudarshana Dhanarath Mardolkar ◽  
A. V. Salker
Keyword(s):  
Visible Region ◽  
Photoluminescence Property ◽  
Precipitation Method ◽  
Magnetic Studies ◽  
Dielectric Parameters ◽  
Chemical Route ◽  
Wide Range ◽  
Lower Temperature ◽  
Co Precipitation ◽  
First Time

Abstract A series of pristine and nickel doped copper tellurates possessing a wide range of applications are studied here. Use of a simple wet chemical route that is co-precipitation method has been employed for the first time, which involves the formation of desired compounds at a relatively lower temperature, thus modifying their properties. All the prepared compounds are characterized and investigated by XRD, TG – DTA, XPS, SEM, TEM to examine their phase purity, thermal stability, chemical state, and microstructural properties. The electrical resistivity studies showed an insulator - semiconductor transition behavior. Magnetic studies revealed the paramagnetic nature of the material. Antiferromagnetic to paramagnetic transition was observed at T N ~ 60 K in case of Cu 2.7 Ni 0.3 TeO 6 sample. Thermoelectric studies indicated a change in conduction mechanism with temperature. Dielectric properties with respect to frequency showed an increase in dielectric parameters with increasing dopant content. Photoluminescence property has been studied and found to show emission in the visible region.

scholarly journals Precise Determination of Optical Band Gap in Cr-Doped Semiconductor Nanowires

2021 ◽  
Author(s):  
N. S. Anad ◽  
Zakaria M Abd El-Fattah ◽  
M. Attallah ◽  
Hanaa M. Ahmed ◽  
Mohammed M. El-Okr ◽  
...  
Keyword(s):  
Band Gap ◽  
Absorption Edge ◽  
Optical Band Gap ◽  
Precise Determination ◽  
Precipitation Method ◽  
Structure Characteristic ◽  
Optical Transitions ◽  
Optical Resonance ◽  
Co Precipitation ◽  
Cr Doping

Abstract Pristine and chromium-doped ZnO nanowires were prepared following the traditional co-precipitation method. X-ray diffraction data identified a pure wurtzite hexagonal crystal structure characteristic for ZnO, irrespective of the doping level. The particle size, as deduced form Williamson–Hall plots, was found to be 45-55 nm for all samples. Scanning electron microscopy revealed a clear nanowires morphology for the pure and doped samples, while elemental analysis ensured the successful Cr-doping. Distinct spectroscopic signatures of Cr-doping were revealed from a detailed deconvolution process applied to optical spectra of doped samples, where Cr 3+ optical transitions were unambiguously identified at ~420 and ~665 nm. Particularly relevant, is the spectral decomposition here performed for the superimposed absorption edge (~385 nm) and Cr 3+ optical resonance at ~420 nm, allowing to claim practically doping-independent optical band gap behavior in the present doping regime. This is further supported by identifying the characteristic ZnO near edge photoluminescence peak (~ 392 nm) which maintains fixed wavelength after Cr-doping. These findings contrast earlier studies on Cr-doped semiconductor nanoparticles and glass systems where the optical band gap has been largely underestimated. We attribute the inconsistence band gap values reported in literature for Cr-doped semiconductors to the proximity of Cr optical transitions to the semiconductor absorption edge.

scholarly journals The Starting Material Concentration Dependence of Ag3PO4 Synthesis for Rhodamine B Photodegradation under Visible Light Irradiation

2020 ◽  
Vol 6 (1) ◽  
pp. 1-9
Author(s):  
Febiyanto Febiyanto ◽  
Uyi Sulaeman
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Rhodamine B ◽  
Visible Region ◽  
Starting Material ◽  
Light Irradiation ◽  
Precipitation Method ◽  
Photocatalytic Activities ◽  
Facet Plane ◽  
Co Precipitation

Synthesis of Ag3PO4 photocatalyst under the varied concentrations of AgNO3 and Na2HPO4·12H2O as starting material has been successfully synthesized using the co-precipitation method. The concentration of AgNO3 is 0.1; 0.5; 1.0; and 2.0 M, whereas Na2HPO4·12H2O is 0.03; 0.17; 0.33; and 0.67 M, respectively. The co-precipitations were carried out under aqueous solution. As-synthesized photocatalysts were examined to degrade Rhodamine B (RhB) under blue light irradiation. The results showed that varying concentrations of starting materials affect the photocatalytic activities, the intensity ratio of [110]/[200] facet plane, and their bandgap energies of Ag3PO4 photocatalyst. The highest photocatalytic activity of the sample was obtained by synthesized using the 1.0 M of AgNO3 and 0.33 M of Na2HPO4·12H2O (AP-1.0). This is due to the high [110] facet plane and increased absorption along the visible region of AP-1.0 photocatalyst. Therefore, this result could be a consideration for the improvement of Ag3PO4 photocatalyst.

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