STRUCTURAL, OPTICAL, ELECTRICAL AND DIELECTRIC PROPERTIES OF PVA-YCl3 FILMS

2019 ◽  
Vol 26 (02) ◽  
pp. 1850149 ◽  
Author(s):  
E. F. M. EL-ZAIDIA ◽  
SALEEM I. QASHOU ◽  
A. A. A. DARWISH ◽  
T. A. HANAFY
Keyword(s):  
Electric Modulus ◽  
Dielectric Relaxation Time ◽  
X Ray Diffraction ◽  
Dispersion Energy ◽  
Field Frequency ◽  
Single Oscillator Model ◽  
Calculated Activation Energy ◽  
Single Oscillator ◽  
Loss Index ◽  
Xrd Patterns

Polyvinyl alcohol (PVA) films doped with 10[Formula: see text]wt.% of yttrium chloride (YCl[Formula: see text] have been made by casting from their aqueous solutions. The structure of un-annealed and annealed PVA-YCl3 films was studied using X-ray diffraction (XRD) patterns and Fourier-transform infrared spectroscopy (FTIR). Both FTIR and XRD revealed that the crystalline ratio of the studied samples increased due to the effect of annealing. The effect of annealing on the optical properties has been studied. Dispersion of the refractive index was described using the single oscillator model. The single oscillator energy and the dispersion energy were estimated. The calculated optical band gap of all PVA-YCl3 films was 5.0[Formula: see text]eV. The behavior of ac conductivity showed that the conduction mechanism of PVA-YCl3 films was correlated barrier hopping model. The dielectric constant and dielectric loss index were decreased with the increase of the field frequency. The electric modulus granted a straightforward technique for assessing the dielectric relaxation time. The calculated activation energy obtained from the electric modulus mechanism was 0.172[Formula: see text]eV.

scholarly journals Estimation of optical parameters of silicon single crystals with different orientations

2019 ◽  
Vol 37 (1) ◽  
pp. 65-70
Author(s):  
M.M. El-Nahass ◽  
H.A.M. Ali
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Single Crystals ◽  
Energy Gap ◽  
Optical Parameters ◽  
Dispersion Energy ◽  
High Frequency Dielectric Constant ◽  
Single Oscillator Model ◽  
Indirect Allowed Transition ◽  
Single Oscillator

AbstractOptical properties of Si single crystals with different orientations (1 0 0) and (1 1 1) were investigated using spectrophotometric measurements in a spectral range of 200 nm to 2500 nm. The data of optical absorption revealed an indirect allowed transition with energy gap of 1.1 ± 0.025 eV. An anomalous dispersion in refractive index. The normal dispersion of the refractive index was discussed according to Wemple-DiDomenico single oscillator model. The oscillator energy Eo, dispersion energy Ed, high frequency dielectric constant ∈∞, lattice dielectric constant ∈L and electronic polarizability αe were estimated. The real ∈1 and imaginary ∈2 parts of dielectric constant were also determined.

scholarly journals Quantum Effects of Indium/Ytterbium Doping on ZnO-Like Nano-Condensed Matter in terms of Urbach-Martienssen and Wemple-DiDomenico Single-Oscillator Models Parameters

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
A. Boukhachem ◽  
B. Ouni ◽  
A. Bouzidi ◽  
A. Amlouk ◽  
K. Boubaker ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Optical Measurements ◽  
Model Parameters ◽  
Range Analysis ◽  
Dispersion Energy ◽  
Structural Investigations ◽  
Glass Substrates ◽  
Single Oscillator Model ◽  
Single Oscillator ◽  
Ytterbium Doping

Conducting and transparent optical ZnO thin films were deposited on glass substrates by a simple mini spray technique. Alternatively, some of the obtained films were doped with indium and ytterbium at the molar rates of: 1, 2, and 3% (In) and 100, 200, and 300 ppm (Yb). In addition to the classical structural investigations including XRD, microhardness vickers (Hv), and optothermal techniques, thorough optical measurements have been carried out for comparison purposes. The refractive indices and the extinction coefficients of the differently doped layers have been deduced from their transmission-reflection spectra over an extended wavelength range. Analysis of the refractive index data through Wemple-DiDomenico single oscillator model yielded quantum characteristics along with the values of long-wavelength dielectric constant, average oscillator wavelength, average oscillator strength, average oscillator energy and dispersion energy. Real and imaginary parts of dielectric constant have also been used to calculate free carrier plasma resonance frequency, optical relaxation time, and free carriers concentration-to-effective mass ratio. Finally, analysis of Urbach-Martienssen model parameters allowed proposing nanoscale explanations to the divergence about doping-related evolution of Urbach tails, this intriguing item having been intensively discussed in the literature in the last decades.

Study of Optical and Structure Properties for Different Composition Tin-Antimony-Selenium Thin Film

2011 ◽  
Vol 227 ◽  
pp. 43-48
Author(s):  
Farid M. Abdel-Rahim
Keyword(s):  
Thin Films ◽  
Electron Microscope ◽  
Photon Absorption ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Single Oscillator Model ◽  
Transmission Electron ◽  
Single Oscillator ◽  
Degree Of Crystallization ◽  
Structure Properties

Amorphous Se100-x (Sn Sb)x glasses with (0 ≤ x ≤ 20 at. %) were prepared by the usual melt quench technique. Thin films for these compositions were prepared by thermal evaporation onto ultrasonically cleaned glass substrates kept at room temperature. From the spectral dependence of the absorption coefficient, a direct electronic transition was mainly responsible for the photon absorption inside these films. The effects of composition on the optical properties of Se100-x(Sn Sb) x thin films was investigated. The refractive index, n, for the as-prepared and annealed films has been analyzed according to the Wwmple–DiDominico single oscillator model. The effect of addition (Sn Sb) on the nature and degree of crystallization has been investigated by studying the structure using transmission electron microscope, X-ray diffraction and scanning electron microscope.

scholarly journals Influence of Bath Temperature and Deposition Time on Topographical and Optical Properties of Nanoparticles ZnS Thin Films Synthesized by a Chemical Bath Deposition Method

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Raghad Zein ◽  
Ibrahim Alghoraibi
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Chemical Bath Deposition ◽  
Deposition Time ◽  
Bath Temperature ◽  
Oscillator Model ◽  
Homogeneous Distribution ◽  
Dispersion Energy ◽  
Single Oscillator Model ◽  
Single Oscillator

In this paper, zinc sulfide nanoparticle (ZnS-NP) thin films were deposited onto glass substrates by chemical bath deposition using zinc sulfate as the cation precursor and thiourea as the anionic precursor. Different bath temperatures (65, 70, 75, and 80°C) and different deposition times (20, 30, 40, and 50 min) were selected to study the performance of ZnS thin films. Topographical and optical characterizations of the films were studied using the atomic force microscope (AFM) and UV-Vis spectroscope. The best ZnS thin films were deposited at a bath temperature (70°C) and a deposition time (30 min) with homogeneous distribution, high density, and small average diameter (106 nm). The energy gap (Eg) was found to be in the range of 4.05-3.97 eV for the ZnS films. Optical constants (refractive index, n, extinction coefficient, k, and dielectric constant, ε) of the films were obtained in the wavelength range 300-500 nm by using spectrophotometric measurement. The dispersion of the refractive index is analyzed by using a single oscillator model. The oscillator energy E0 and dispersion energy Ed were determined using the Wemple-DiDomenico single oscillator model. Urbach’s energy increases from 0.907 eV to 2.422 eV with increasing of deposition time. The calculated radius of nanoparticles using Brus equation was 1.9, 2.3, 2.45, and 2.51 nm at deposition times 20, 30, 40, and 50 min, respectively.

Structural and Magnetic Hysteresis Properties of Co-Zr Substituted Hexagonal Barium Ferrites

2015 ◽  
Vol 7 (1) ◽  
pp. 1346-1351
Author(s):  
Ch.Gopal Reddy ◽  
Ch. Venkateshwarlu ◽  
P. Vijaya Bhasker Reddy
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Magnetic Hysteresis ◽  
Grain Morphology ◽  
Hexagonal Structure ◽  
Ion Composition ◽  
X Ray Diffraction ◽  
Ceramic Method ◽  
Barium Ferrites ◽  
Xrd Patterns

Co-Zr substituted M-type hexagonal barium ferrites, with chemical formula BaCoxZrxFe12-2xO19 (where x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0), have been synthesized by double sintering ceramic method. The crystallographic properties, grain morphology and magnetic properties of these ferrites have been investigated by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM). The XRD patterns confirm the single phase with hexagonal structure of prepared ferrites. The magnetic properties have been investigated as a function of Co and Zr ion composition at an applied field in the range of 20 KOe. These studies indicate that the saturation magnetization (Ms) in the samples increases initially up to the Co-Zr composition of x=0.6 and decreases thereafter. On the other hand, the coercivity (Hc) and Remanent magnetization (Mr) are found to decrease continuously with increasing Co-Zr content. This property is most useful in permanent magnetic recording. The observed results are explained on the basis of site occupation of Co and Zr ions in the samples.

scholarly journals Crystal Structure and Computational Study on Methyl-3-Aminothiophene-2-Carboxylate

Crystals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 19 ◽  
Author(s):  
Yaping Tao ◽  
Ligang Han ◽  
Andong Sun ◽  
Kexi Sun ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Crystal Packing ◽  
Computational Study ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Dispersion Energy ◽  
Monoclinic Crystal ◽  
Hydrogen Bond Interactions ◽  
Calculation Results ◽  
Reduced Density Gradient ◽  
Reduced Density

Methyl-3-aminothiophene-2-carboxylate (matc) is a key intermediate in organic synthesis, medicine, dyes, and pesticides. Single crystal X-ray diffraction analysis reveals that matc crystallizes in the monoclinic crystal system P21/c space group. Three matc molecules in the symmetric unit are crystallographically different and further linked through the N–H⋯O and N–H⋯N hydrogen bond interactions along with weak C–H⋯S and C–H⋯Cg interactions, which is verified by the three-dimensional Hirshfeld surface, two-dimensional fingerprint plot, and reduced density gradient (RDG) analysis. The interaction energies within crystal packing are visualized through dispersion, electrostatic, and total energies using three-dimensional energy-framework analyses. The dispersion energy dominates in crystal packing. To better understand the properties of matc, electrostatic potential (ESP) and frontier molecular orbitals (FMO) were also calculated and discussed. Experimental and calculation results suggested that amino and carboxyl groups can participate in various inter- and intra-interactions.

scholarly journals Influence of Li2CO3 addition on electrical and magnetic properties of Ni0.6Mg0.4Fe2O4

2020 ◽  
Vol 10 (03) ◽  
pp. 2050003
Author(s):  
M. R. Hassan ◽  
M. T. Islam ◽  
M. N. I. Khan
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Low Frequency ◽  
Solid State Reaction Method ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Frequency Regime ◽  
Xrd Patterns

In this research, influence of adding Li2CO3 (at 0%, 2%, 4%, 6%) on electrical and magnetic properties of [Formula: see text][Formula: see text]Fe2O4 (with 60% Ni and 40% Mg) ferrite has been studied. The samples are prepared by solid state reaction method and sintered at 1300∘C for 6[Formula: see text]h. X-ray diffraction (XRD) patterns show the samples belong to single-phase cubic structure without any impurity phase. The magnetic properties (saturation magnetization and coercivity) of the samples have been investigated by VSM and found that the higher concentration of Li2CO3 reduces the hysteresis loss. DC resistivity increases with Li2CO3 contents whereas it decreases initially and then becomes constant at lower value with temperature which indicates that the studied samples are semiconductor. The dielectric dispersion occurs at a low-frequency regime and the loss peaks are formed in a higher frequency regime, which are due to the presence of resonance between applied frequency and hopping frequency of charge carriers. Notably, the loss peaks are shifted to the lower frequency with Li2CO3 additions.

Synthesis and Characterization of Multiferroic NiFe2O4/BiFeO3 Nanocomposites by Modified Pechini Method

2011 ◽  
Vol 197-198 ◽  
pp. 456-459
Author(s):  
Xian Ming Liu ◽  
Wen Liang Gao
Keyword(s):  
Pechini Method ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Magnetic Bias ◽  
Field Frequency ◽  
Magnetic Field Frequency ◽  
X Ray ◽  
Structure And Morphology ◽  
Modified Pechini Method

Spinel-perovskite multiferroics of NiFe2O4/BiFeO3 nanoparticles were prepared by modified Pechini method. The structure and morphology of the composites were examined by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the composites consisted of spinel NiFe2O4 and perovskite BiFeO3 after annealed at 700°C for 2h, and the particle size ranges from 40 to 100nm. VSM and ME results indicated that the nanocomposites exhibited both tuning magnetic properties and a ME effect. The ME effect of the nanocomposites strongly depended on the magnetic bias and magnetic field frequency.

Determination of crystallinity of Chinese handmade papers by means of X-ray diffraction

2020 ◽  
Vol 41 (2) ◽  
pp. 69-86
Author(s):  
Peng Liu ◽  
Hongbin Zhang ◽  
Sinong Wang ◽  
Hui Yu ◽  
Bingjie Lu ◽  
...  
Keyword(s):  
Negative Influence ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Eulaliopsis Binata ◽  
Different Types ◽  
Powder Samples ◽  
Xrd Patterns ◽  
Xrd Method

AbstractThe crystallinity indices (CrI) of Chinese handmade papers were investigated using the X-ray diffraction (XRD) method. Four Chinese handmade papers, Yingchun, Zhuma, Yuanshu and Longxucao papers were used as model substrates of mulberry bark, ramie, bamboo and Eulaliopsis binata papers, respectively. Two forms of the paper samples, paper sheets and their comminuted powders, were used in this study. The results showed that their XRD patterns belong to the cellulose-I type and Iβ dominates the cellulose microstructure of these paper samples. Moreover, it was found that the microstructures and CrIs of cellulose of these papers were changed by the grinding treatment. This work suggested that the sheet form of the handmade papers is suitable to determine CrI by XRD, despite the contribution of non-cellulosic components in the papers. The order of CrIs for these paper sheet samples was Yingchun, Zhuma, Longxucao and Yuanshu papers. Besides CrIs, differences in cross-sectional areas of the crystalline zone of cellulose can be used for comparing different types of handmade papers. It was also found that the CrIs and crystallite size of paper cellulose varied between the sheet samples and the powder samples, illustrating that the pulverisation has a negative influence on the microstructure of the handmade papers.

A Fast Synthesis and Sintering of Mg2Si1−xSnx (0≤x≤1.0) Solid Solutions by Microwave Irradiation

2011 ◽  
Vol 197-198 ◽  
pp. 417-420 ◽  
Author(s):  
Shu Cai Zhou ◽  
Chen Guang Bai ◽  
Chun Lin Fu
Keyword(s):  
Microwave Irradiation ◽  
Solid Solutions ◽  
Microwave Assisted Synthesis ◽  
Green Density ◽  
X Ray Diffraction ◽  
Power Setting ◽  
Xrd Patterns ◽  
Heating Behavior ◽  
Fast Synthesis ◽  
Lower Heating

In order to reduce the oxidizing and volatilizing caused by Mg element in the traditional methods for synthesizing Mg2Sil-xSnxsolid solutions, Mg2Sil-xSnxsolid solutions have been prepared by Microwave-assisted Synthesis techniques. The heating behavior of Mg, Si and Sn fixed powder was investigated under microwave irradiation. X-ray diffraction (XRD) was used to characterize the powders. The results suggest that the temperature-rising rate is also dependent on the initial green density and higher green density provides lower heating rate while power setting are fixed. XRD patterns show that Mg2Sil-xSnxsolid solutions have been well formed under microwave irradiation.

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