scholarly journals Influence of aluminium concentration in Zn0:9V0:1O nanoparticles on structural and optical properties

2015 ◽  
Vol 33 (1) ◽  
pp. 198-204 ◽  
Author(s):  
A. Sayari ◽  
L. El Mir ◽  
S. Al-Heniti ◽  
T. Al-Harbi ◽  
S. J. Yaghmour ◽  
...  
Keyword(s):  
Optical Properties ◽  
Sol Gel ◽  
Wurtzite Structure ◽  
Gravimetric Analysis ◽  
Structural And Optical Properties ◽  
Al Content ◽  
Crystallite Sizes ◽  
Direct Band ◽  
Agglomeration Of Nanoparticles ◽  
Xrd Patterns

AbstractThe (V,Al) co-doped ZnO nano-structured powders (Zn0.9-xV0.1AlxO, where x = 0.02, 0.03 and 0.04) were synthesized via the sol-gel technique and their structural and optical properties were investigated. The effect of Al concentration on the structural and optical properties of the Zn0.9-xV0.1AlxO nanopowders was studied using various techniques. The XRD patterns indicate that the samples have a polycrystalline wurtzite structure. The crystallite size increases with increasing the Al content and lies in the range of 23 to 30 nm. The lattice strain, estimated by the Stokes-Wilson equation, decreases when Al content increases. SEM and TEM micrographs show that Zn0.9-xV0.1AlxO powders are the agglomeration of nanoparticles having spherical and hexagonal shapes with dimensions ranging from 20 to 30 nm. FT-IR spectra show a distinct absorption peak at about 500 cm-1 for ZnO stretching modes and other peaks related to OH and H2O bands. Raman spectra confirm the wurtzite structure of the Zn0.9-xV0.1AlxO nanoparticles. The direct band gaps of the synthesized Zn0.9-xV0.1AlxO nanopowders, estimated from the Brus equation and the crystallite sizes deduced from XRD, are around 3.308 eV. The decomposition process of the dried gel system was investigated by thermal gravimetric analysis (TGA).

scholarly journals Synthesis and comparative study on the structural and optical properties of ZnO doped with Ni and Ag nanopowders fabricated by sol gel technique

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Al-Ariki ◽  
Nabil A. A. Yahya ◽  
Sua’ad A. Al-A’nsi ◽  
M. H. Hj Jumali ◽  
A. N. Jannah ◽  
...  
Keyword(s):  
Optical Properties ◽  
Sol Gel ◽  
Visible Region ◽  
Average Crystallite Size ◽  
Band Gaps ◽  
Structural And Optical Properties ◽  
Crystallite Sizes ◽  
Gel Technique ◽  
Uv Visible ◽  
Xrd Patterns

AbstractIn this work we have tried to prepare Ni and Ag doped ZnO nanopowders using the sol gel technique. The influence of Ni and Ag (1, 3 and 5 mol.%) on the crystalline structure and optical properties of ZnO was investigated. The samples were characterized by XRD, FTIR and UV–visible spectrophotometer. XRD patterns confirmed the wurtzite formation of doped and undoped ZnO nanopowders. The average crystallite sizes of the prepared samples found from XRD were 19 nm for undoped ZnO, from 17 to 22 nm for Ni-ZnO and from 19 to 26 nm for Ag-ZnO. The average crystallite size of Ag-ZnO increased with increasing Ag contents. Different optical properties of Ni-ZnO and Ag-ZnO nanopowders were observed for different Ni and Ag content. The band gaps of Ni-ZnO and Ag-ZnO nanopowders were lower than that of the undoped ZnO (3.1 eV). The band gaps of Ag-ZnO were lower than that of Ni-ZnO. The optical properties of ZnO were enhanced by Ni (mol.%) in the UV region and by Ag (3 and 5 mol.%) in the visible region.

scholarly journals Effect of Annealing Temperature on the Structural and Optical Properties of TiO2 Thin Film Prepared by Sol-gel Method

2016 ◽  
Vol 8 (3) ◽  
pp. 267-272 ◽  
Author(s):  
F. U. Khan ◽  
M. Zubair ◽  
M. Z. Ansar ◽  
M. K. Alamgir ◽  
S. Nadeem
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Surface Morphology ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Rutile Phase ◽  
Structural And Optical Properties ◽  
Tio2 Thin Films ◽  
Different Temperatures ◽  
Xrd Patterns

The effect of annealing temperatures on the surface morphology and optical properties of titanium dioxide (TiO2) thin films deposited by spin coating on Silicon substrate was studied. The TiO2 thin films deposited onto silicon substrates were annealed at different temperatures. The structural and optical properties were studied using scanning electron microscopy (SEM), X-ray diffraction technique (XRD) and optical ellipsometer. The results indicated that the structural properties of the TiO2 thin films were changed with the increase in annealing temperature. The SEM investigation showed that as annealing temperature was increased, the grain and pores size were increased. The XRD patterns of the studied samples showed that rutile phase were found in a sample annealed at high temperature. The ellipsometry investigation shows that the refractive index increased while energy band gap decreased with the annealing temperature. The results showed that surface porosity, optical properties and surface morphology of TiO2 could be affected by changing the annealing temperature.   

The effects of different polymerization agents on structural and optical properties of (K0.5Na0.5)NbO3 nanopowders synthesized by a facile green route

2014 ◽  
Vol 28 (28) ◽  
pp. 1450224 ◽  
Author(s):  
Gh. H. Khorrami ◽  
A. Kompany ◽  
A. Khorsand Zak
Keyword(s):  
Optical Properties ◽  
Sol Gel ◽  
Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Energy Band Gap ◽  
Structural And Optical Properties ◽  
Transmission Electron ◽  
Green Route ◽  
Xrd Patterns ◽  
Average Size

( K 0.5 N 0.5) NbO 3 lead-free nanopowders were synthesized by a modified sol–gel method in different media: gelatin, starch and chitosan, as polymerization and stabilizer agents. The proper temperature needed for calcinating the prepared gel was obtained using thermogravometric analysis (TGA). Structural and optical properties of the prepared powders were investigated and compared using X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-Vis diffused reflectance spectroscopy. The XRD patterns of the synthesized samples confirmed the formation of the orthorhombic structure at 600°C calcination temperature with no remarkable extra peaks. TEM images showed that the morphologies of the particles prepared in the three different media are cubic with the average size of about 69, 34 and 49 nm for gelatin, starch and chitosan, respectively. The value of the energy band gap of the samples was calculated by diffused reflectance spectroscopy, using Kubelka–Munk method. Our results showed that the type of the polymerization agent is important in preparing KNN nanoparticles and affects the structural and optical properties of the synthesized samples.

Structural and optical properties of KNN nanocubes synthesized by a green route using gelatin

2015 ◽  
Vol 08 (02) ◽  
pp. 1550030 ◽  
Author(s):  
Gh. H. Khorrami ◽  
A. Kompany ◽  
A. Khorsand Zak
Keyword(s):  
Optical Properties ◽  
Sol Gel ◽  
Structural Deformation ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Transmission Electron ◽  
Green Route ◽  
Vis Spectroscopy ◽  
Xrd Patterns ◽  
Average Size

Sodium potassium niobate nanoparticles [( K 0.5 Na 0.5) NbO 3, KNN ], KNN-NPs, were synthesized using a modified sol–gel method. Structural and optical properties of the prepared samples were investigated by thermogravometric analyzer (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman and UV–Vis spectroscopy. The XRD patterns showed that the formation of the orthorhombic KNN-NPs starts at 500°C calcination temperature. Raman spectroscopy was used to investigate the crystalline symmetry and the structural deformation of the prepared KNN-NPs. TEM images showed that the morphology of the prepared particles is cubic, with the average size of about 50 nm. From diffused reflectance spectroscopy along with using Kubelka–Munk method, the energy bandgaps were determined to be indirect with the values of 3.13 eV and 3.19 eV for the samples calcined at 500°C and 600°C, respectively.

Structural and optical properties of Fe-doped TiO2 films by sol–gel method

2020 ◽  
Vol 34 (31) ◽  
pp. 2050345
Author(s):  
S. B. Shi
Keyword(s):  
Optical Properties ◽  
Raman Spectra ◽  
Anatase Phase ◽  
Sol Gel ◽  
Fe Doping ◽  
Structural And Optical Properties ◽  
Free Hole ◽  
Defect Sites ◽  
Coating Method ◽  
Xrd Patterns

Fe-doped TiO2 films were prepared by sol–gel spin coating method. After annealing in vacuum, the structural and optical properties of the films were investigated. XRD patterns revealed that all diffraction peaks can be attributed to TiO2 with anatase phase structure. No segregated phases are present in the samples within XRD detection limit. XPS results indicated that iron element exists in a tervalent state and incorporates into TiO2 lattice. Raman spectra demonstrated that all the films are in pure anatase phase. No other vibration modes in the spectra were detected. Raman spectra are consistent with the results of XRD patterns. Photoluminescence spectra at room temperature are sensitive to the concentration of Fe doping. The quenching increases with the increase in amount of dopant, which can be due to the introduction of defect sites such as oxygen vacancy by Fe doping. The free hole can interact with a trapped electron, or a free electron can interact with a trapped hole, resulting in non-radiative.

Influence of Cd doping on structural and optical properties of (Cd, Al)-codoped ZnO powders synthesized via sol–gel method

2015 ◽  
Vol 645 ◽  
pp. 529-534 ◽  
Author(s):  
Libing Duan ◽  
Xiaoru Zhao ◽  
Yajun Wang ◽  
Hao Shen ◽  
Wangchang Geng ◽  
...  
Keyword(s):  
Optical Properties ◽  
Sol Gel ◽  
Structural And Optical Properties ◽  
Gel Method ◽  
Sol Gel Method ◽  
Cd Doping ◽  
Zno Powders

scholarly journals Co doping induced structural and optical properties of sol–gel prepared ZnO thin films

2014 ◽  
Vol 318 ◽  
pp. 309-313 ◽  
Author(s):  
Ebru Gungor ◽  
Tayyar Gungor ◽  
Deniz Caliskan ◽  
Abdullah Ceylan ◽  
Ekmel Ozbay
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Sol Gel ◽  
Zno Thin Films ◽  
Structural And Optical Properties ◽  
Co Doping

scholarly journals Structural and optical properties of SnO2–Al2O3 nanocomposite synthesized via sol-gel route

2015 ◽  
Vol 33 (4) ◽  
pp. 714-718 ◽  
Author(s):  
Neeraj K. Mishra ◽  
Chaitnaya Kumar ◽  
Amit Kumar ◽  
Manish Kumar ◽  
Pratibha Chaudhary ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Properties ◽  
Sol Gel ◽  
Physical Interaction ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Sensing Applications ◽  
Scanning Electron

AbstractA nanocomposite of 0.5SnO2–0.5Al2O3 has been synthesized using a sol-gel route. Structural and optical properties of the nanocomposite have been discussed in detail. Powder X-ray diffraction and scanning electron microscopy with energy-dispersive X-ray diffraction spectroscopy confirm the phase purity and the particle size of the 0.5SnO2–0.5Al2O3 nanocomposite (13 to 15 nm). The scanning electron microscopy also confirms the porosity in the sample, useful in sensing applications. The FT-IR analysis confirms the presence of physical interaction between SnO2 and Al2O3 due to the slight shifting and broadening of characteristic bands. The UV-Vis analysis confirms the semiconducting nature because of direct transition of electrons into the 0.5SnO2–0.5Al2O3 nanocomposites.

Structural and Optical Properties of Al Co-Doped ZnCoO Thin Film

2014 ◽  
Vol 989-994 ◽  
pp. 656-659
Author(s):  
Ping Cao ◽  
Yue Bai
Keyword(s):  
Thin Film ◽  
Optical Properties ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Al Doping ◽  
X Ray ◽  
Uv Emission ◽  
Uv Absorption Spectroscopy ◽  
Co Doped

Al co-doped ZnCoO thin film has been prepared by a sol-gel method. The structural and optical properties of the sample were investigated. X-ray diffraction and UV absorption spectroscopy analyses indicate that Al3+ and Co2+ substitute for Zn2+ without changing the wurtzite structure. With the Al doping, the visible emission increased and the UV emission decreased, which is attributed to the increase of O vacancies and Zn interstitials.

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