Optical Properties of Lithium Borate Glass Containing Barite

2021 ◽  
Vol 406 ◽  
pp. 441-447
Author(s):  
K. Abdellaoui
Keyword(s):  
Optical Properties ◽  
Optical Transmittance ◽  
Refraction Index ◽  
Molar Refraction ◽  
Calculated Density ◽  
Alumina Crucible ◽  
Prepared Glass ◽  
Optical Dielectric Constant ◽  
Optical Dielectric ◽  
Lithium Borate Glass

Through this research we have prepared samples of glass, which includes 60 mol%B2O3 – x mol %barite – (40-x) mol %Li2O, where x= 5, 7.5, 10, and 15 mol%. The samples fabricated by the melt quenching technique. The samples are melted in alumina crucible at 1473 K for 1.5 h in an electric muffle furnace (LENTON). The glasses were casted into stainless molds, and then immediately transferred to an annealing furnance at about 400°C. The aim of this work is to determine the extent of the effect of raw barite on the physical and optical properties of this glass. The optical transmittance and reflectance spectrum of the glasses in this work were determined in the wavelength range 300–2500 nm at room temperature. The physical and optical properties of the following prepared glass samples have been determined and calculated (density, volume molar, refraction index, Optical dielectric constant, molar refractivity and electronic polarizability) for glasses prepared.

scholarly journals A Comprehensive Review on Optical Properties of Polymer Electrolytes and Composites

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3675 ◽  
Author(s):  
Shujahadeen B. Aziz ◽  
M. A. Brza ◽  
Muaffaq M. Nofal ◽  
Rebar T. Abdulwahid ◽  
Sarkawt A. Hussen ◽  
...  
Keyword(s):  
Optical Properties ◽  
Dielectric Loss ◽  
Band Gap ◽  
Polymer Electrolytes ◽  
Optical Band Gap ◽  
Review Paper ◽  
Good Thermal Stability ◽  
Optical Dielectric Constant ◽  
Loss Parameter ◽  
Optical Dielectric

Polymer electrolytes and composites have prevailed in the high performance and mobile marketplace during recent years. Polymer-based solid electrolytes possess the benefits of low flammability, excellent flexibility, good thermal stability, as well as higher safety. Several researchers have paid attention to the optical properties of polymer electrolytes and their composites. In the present review paper, first, the characteristics, fundamentals, advantages and principles of various types of polymer electrolytes were discussed. Afterward, the characteristics and performance of various polymer hosts on the basis of specific essential and newly published works were described. New developments in various approaches to investigate the optical properties of polymer electrolytes were emphasized. The last part of the review devoted to the optical band gap study using two methods: Tauc’s model and optical dielectric loss parameter. Based on recently published literature sufficient quantum mechanical backgrounds were provided to support the applicability of the optical dielectric loss parameter for the band gap study. In this review paper, it was demonstrated that both Tauc’s model and optical dielectric loss should be studied to specify the type of electron transition and estimate the optical band gap accurately. Other parameters such as absorption coefficient, refractive index and optical dielectric constant were also explored.

SYNTHESIS AND CHARACTERIZATION OF (ZNO)–(CO3O4) NANOCOMPOSITE VIA SPRAY PYROLYSIS PROCESS: THE USE OF THE BRUGGEMAN MODEL ON OPTICAL PROPERTIES PREVISION

2021 ◽  
pp. 2150066
Author(s):  
K. M. E. BOUREGUIG ◽  
H. TABET-DERRAZ ◽  
T. SEDDIK ◽  
M. A. BENALI
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
Optical Properties ◽  
Band Gap ◽  
Spray Pyrolysis ◽  
Effective Dielectric Constant ◽  
Nanocomposite Thin Film ◽  
Bruggeman Model ◽  
Optical Dielectric Constant ◽  
Optical Dielectric

In the present paper, (ZnO)–(Co3O4) nanocomposite thin films have been prepared by using spray pyrolysis deposition on a glass substrate at 350∘C. After that, the as-obtained films have been characterized and analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and the double beam UV-visible (UV-vis) spectrophotometer. Furthermore, the Bruggeman model is used to predict the evolution of the optical dielectric constant (real and imaginary parts: [Formula: see text] and [Formula: see text] to compare them with those obtained from the experimental results. The XRD pattern reveals that the nanocomposite film has diffraction peaks 2[Formula: see text], 36.95∘ corresponding respectively to the (220), (311) planes of cubic Co3O4 and another about of 2[Formula: see text] corresponding to the (101) plane of Wurtzite ZnO. Using the Debye Scherrer formula, the crystallite size of (ZnO)[Formula: see text]–(Co3O[Formula: see text] nanocomposite is found about 32[Formula: see text]nm, while the obtained thickness of this nanocomposite is about 780[Formula: see text]nm using the DekTak Stylus profilometer. Besides, the morphology analysis shows that the nanocomposite sample is well covered without holes and/or cracks and it has uniform dense grains. The evaluation of the transmittance, reflectance, refraction index, extinction coefficient, real and imaginary parts of dielectric constant as function of wavelength illustrates that the optical response of nanocomposite thin film (ZnO)[Formula: see text]–(Co3O[Formula: see text] depends on the influence of two mediums of pure materials ZnO and Co3O4 and their interaction. In addition, the direct band gap vs incident photon energy obtained from the Tauc plot equation shows that this nanocomposite has three values of band gap energy which are [Formula: see text][Formula: see text]eV, [Formula: see text][Formula: see text]eV (correspond to pure Co3O4 film) and [Formula: see text][Formula: see text]eV (correspond to pure ZnO film). Besides, the application of the Bruggeman equation indicates that the influence of the values of volume concentration and optical dielectric constant of the ingredient nanomaterials (ZnO and Co3O[Formula: see text] is significant on the value of the effective dielectric constant of nanocomposite thin film. The specific result of this study is the similarity between the spectra obtained from the Bruggeman model and the measured one, which proves that the application of this model is useful for the prediction of the optical properties of the composite.

scholarly journals UV-A Treatment of ZrO2 Thin Films Fabricated by Environmental Friendlier Water-Based Solution Processing: Structural and Optical Studies

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 821
Author(s):  
Aneeqa Bashir ◽  
Mehwish Farooq ◽  
Abdul Malik ◽  
Shahzad Naseem ◽  
Arshad Saleem Bhatti
Keyword(s):  
Optical Properties ◽  
Low Cost ◽  
Annealed Film ◽  
Optical Transmittance ◽  
Amorphous Structure ◽  
Solution Processing ◽  
Vis Spectroscopy ◽  
Water Based ◽  
Free Films ◽  
Quartz Substrates

An environmentally friendlier solution processing has been introduced to fabricate zirconium oxide (ZrO2) films on quartz substrates, using spin coating of simple water-based solution. The films cured with UV-A = 330 nm for different times (40, 80, 120 min) were investigated for structural and optical properties and compared with thermally annealed film (at 350 °C). XRD and Raman spectroscopy showed amorphous structure in all the samples with no significant phase transformation with UV-A exposure. AFM microscopy showed smooth and crack free films with surface roughness ≤2 nm that reduced with UV-A exposure. Ultraviolet-visible (UV–Vis) spectroscopy demonstrated optical transmittance ≥88% and energy band gap variations as 4.52–4.70 eV. Optical constants were found from spectroscopic ellipsometry (SE). The refractive index (n) values, measured at 470 nm increased from 1.73 to 2.74 as the UV-A exposure prolonged indicating densification and decreasing porosity of the films. The extinction coefficient k decreased from 0.32 to 0.19 indicating reduced optical losses in the films under the UV-A exposure. The photoluminescence (PL) spectra exhibited more pronounced UV emissions which grew intense with UV-A exposure thereby improving the film quality. It is concluded that UV-A irradiation can significantly enhance the optical properties of ZrO2 films with minimal changes induced in the structure as compared to thermally treated film. Moreover, the present work indicates that water-based solution processing has the potential to produce high-quality ZrO2 films for low cost and environmental friendlier technologies. The work also highlights the use of UV-A radiations as an alternate to high temperature thermal annealing for improved quality.

Singular pole and enhanced sensitivity of PT-symmetric layered structure with resonators

2018 ◽  
Vol 84 (1) ◽  
pp. 10503 ◽  
Author(s):  
Rong-kun Ma ◽  
Jing Xia ◽  
Yun-tuan Fang
Keyword(s):  
Optical Properties ◽  
High Sensitivity ◽  
Refraction Index ◽  
Symmetric System ◽  
Scatter Matrix ◽  
Enhanced Sensitivity ◽  
Symmetric Structure ◽  
Single Cavity ◽  
Total Gain ◽  
Scatter Matrix Method

In order to achieve enhanced transmittance of parity-time (PT)-symmetric system, we design a layered PT-symmetric structure including resonators. We use the scatter matrix method to study the optical properties of the designed structure under the modulation of resonators. The structure system takes on a singular pole effect, i.e., the huge reflectance and transmittance occur at a special wavelength and period number. The field distribution reveals that the singular pole results from the coupling resonance of single cavity and the whole structure. Because of the coupling resonance, the total gain in layer A is much larger than the total loss in layer C. The reflectance and transmittance at the singular pole take on a high sensitivity on the refraction index of the resonators.

Metal Contacts on a-GaN

1996 ◽  
Vol 1 ◽  
Author(s):  
T. U. Kampen ◽  
W. Mönch
Keyword(s):  
Tight Binding ◽  
Image Force ◽  
Schottky Contacts ◽  
Metal Contacts ◽  
Zero Bias ◽  
Barrier Heights ◽  
Current Voltage ◽  
Optical Dielectric Constant ◽  
Optical Dielectric ◽  
Gap States

The Schottky barrier heights of silver and lead contacts on n-type GaN (0001) epilayers were determined from current-voltage characteristics. The zero-bias barrier heights and the ideality factors were found to be linearly correlated. Similar observations were previously reported for metal contacts on Si (111) and GaAs (110) surfaces. The barrier heights of ideal Schottky contacts are characterized by image force lowering of the barrier only. This gives an ideality factor of 1.01. From our data we obtain barrier heights of 0.82 eV and 0.73eV for ideal Ag and Pb contacts on GaN, respectively. The metal-induced gap states (MIGS) model predicts the barrier heights of ideal Schottky contacts on a given semiconductor to be linearly correlated with the electronegativities of the metals. The two important parameters of this MIGS-and-electronegativity model are the charge neutrality level (CNL) of the MIGS and a slope parameter. The CNL may be calculated from the dielectric band gap and using the empirical tight-binding method. The slope parameters are given by the optical dielectric constant of the respective semiconductor. The predictions of the MIGS model for metal/GaN contacts are confirmed by the results presented here and by barrier heights previously reported by others for Au, Ti, Pt, and Pd contacts on GaN.

scholarly journals Effect of thickness on optical properties of pure Epoxy Resin plates

2014 ◽  
Vol 11 (2) ◽  
pp. 554-559
Author(s):  
Baghdad Science Journal
Keyword(s):  
Optical Properties ◽  
Epoxy Resin ◽  
Energy Gap ◽  
Visible Region ◽  
Refraction Index ◽  
Ultraviolet Region ◽  
Intensity Increase ◽  
Absorption Intensity ◽  
Light Region ◽  
Different Thickness

In this study, Epoxy Resin plates was prepared by mixing epoxy(A) and hardner(B)with ratio(A:B) (3:1) with different thickness (0.3-0.96)cm. The effect of thickness on optical properties have been studied (absorption ,transmission ,reflectance) also the optical constant were found like (absorption coefficient, extenuation coefficient and refraction index) for all of the prepared plates. The results have shown that by increasing the thickness of plates., the absorption intensity increase in which at plates thickness (0.3-0.96)cm the absorption intensity were(1.54-1.43) respectively, and since absorption peak for epoxy occur in ultraviolet region and exactly at wavelength(368)nm and energy gap(Eg=3.05 eV) thus their good transmittance in the visible light region The plates have transmittance of about (60-83.4)% in visible region ,the refraction index for Elda epoxy is (n= 1.53 ) and its reflectance is (R=4 )% at wavelength (368 nm).

Energy gap and optical dielectric constant of Pb1−Cd Se films

1987 ◽  
Vol 27 (6) ◽  
pp. 389-397 ◽  
Author(s):  
M. Baleva ◽  
M. Maksimov ◽  
M. Sendova
Keyword(s):  
Dielectric Constant ◽  
Energy Gap ◽  
Optical Dielectric Constant ◽  
Optical Dielectric

Electrical and Optical Properties of Silicone Oil/Carbon Nanotube Nanocomposites

2021 ◽  
Vol 21 (4) ◽  
pp. 2185-2195
Author(s):  
Jeferson Matos Hrenechen ◽  
Celso de Araujo Duarte ◽  
Ney Pereira Mattoso Filho ◽  
Evaldo Ribeiro
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Conduction Mechanism ◽  
Silicone Oil ◽  
Optical Transmittance ◽  
Liquid Matrix ◽  
Electrical And Optical Properties ◽  
Multiwalled Carbon ◽  
Liquid Matrices ◽  
The Matrix

The present work describes the preparation and the investigation of the room temperature electrical and optical properties of a series of liquid nanocomposites (lnC) prepared with different concentrations of multiwalled carbon nanotubes (MWCNT) in a variety of liquid matrices: glycerin, Vaseline, glucose, propylene glycol and silicone oil (SIO). Special attention is deserved to the SIO matrix, owing to its convenient electrical properties for our purposes. We verified that a small percent fraction of MWCNT dispersed along the SIO matrix is capable of improving the electrical conductivity of the matrix by orders of magnitude, indicating that the MWCNT strongly participates in the electrical conduction mechanism. Also, the application of an external electric field to this lnC resulted in large changes in the optical transmittance, that were interpreted as a consequence of the fieldinduced MWCNT alignment into the liquid matrix. The characteristics of such a new category of nanocomposite in the liquid state suggest further studies.

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