Physical and spectroscopic studies on manganese ions in lead halo borate glasses

2017 ◽  
Vol 31 (16) ◽  
pp. 1750180 ◽  
Author(s):  
K. Chandra Sekhar ◽  
Abdul Hameed ◽  
G. Ramadevudu ◽  
M. Narasimha Chary ◽  
Md. Shareefuddin
Keyword(s):  
Optical Band Gap ◽  
Urbach Energy ◽  
Spectroscopic Studies ◽  
Manganese Ions ◽  
X Ray Diffraction ◽  
Ionic Radii ◽  
X Ray ◽  
Prepared Glass ◽  
Splitting Constant

Lead halo borate glass systems containing manganese ions have been investigated to study the role of halide ions on the physical, optical and EPR studies. The amorphous phase of the prepared glass samples [Formula: see text]PbX2–(30[Formula: see text])PbO–69.5B2O3–0.5MnO2 with X = F, Cl and Br and [Formula: see text] mol% was confirmed from their X-ray diffraction spectra. Ionic radii of the halides played an important role in the physical properties. From the optical absorption spectra, optical band gap and Urbach energy values were evaluated. The EPR spectra have shown a six-line hyperfine (HF) structure centered at [Formula: see text] and attributed to Mn[Formula: see text] centers in octahedral symmetry. The other signals at [Formula: see text] and 4.3 were attributed to the rhombic surroundings of Mn[Formula: see text] ions. The negative shift in [Formula: see text]-value revealed highly ionic environment around the Mn[Formula: see text] ion in the glass hosts. The HF splitting constant (A), number of spins (N) and susceptibility [Formula: see text] values of the prepared glasses were also reported.

scholarly journals Structural and spectroscopic analyses of copper doped P2O5-ZnO-K2O-Bi2O3 glasses

2015 ◽  
Vol 9 (3) ◽  
pp. 169-173 ◽  
Author(s):  
Yahia Elbashar
Keyword(s):  
Optical Band Gap ◽  
Band Gap Energy ◽  
Dielectric Constants ◽  
X Ray Diffraction ◽  
Band Tail ◽  
Absorption Data ◽  
X Ray ◽  
Spectroscopic Analyses ◽  
Acceptable Range ◽  
Prepared Glass

Homogeneous glass samples with different compositions 42(P2O5)?40 (ZnO)?(16?x)(K2O)?2 (Bi2O3)?x(Cu2O) (where x = 1, 2 and 3mol%) were prepared by conventional melt-quenched technique under controlled conditions. The structure of the prepared glass samples was investigated by X-ray diffraction. Optical properties (transmittance and reflectance) of the glasses were measured in the wavelength range 200-900 nm. The optical band gap energy of the investigated glasses with 1, 2 and 3mol% Cu2O was estimated from absorption data using the Mott and Davis relation and found to be 2.33, 2.45 and 2.53 eV, respectively. The mechanism of optical absorption was found to be direct. The band tail width was also estimated and found to lay in the acceptable range. Refractive index, absorption coefficient, extinction coefficient and real/imaginary parts of dielectric constants were calculated. Further to this, some theoretical investigation of the spectral problems was carried out. The investigation was based on finite difference method.

Optical Absorption of Er3+/Nd3+ Co-Doped Tellurite Glass

2012 ◽  
Vol 501 ◽  
pp. 96-100 ◽  
Author(s):  
S. Akmar Roslan ◽  
M. Rahim Sahar ◽  
Ramli Arifin ◽  
Sib Krishna Ghoshal ◽  
M. Supar Rohani ◽  
...  
Keyword(s):  
Tellurite Glass ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Tellurite Glasses ◽  
X Ray Diffraction ◽  
Melt Quenching ◽  
X Ray ◽  
Diffraction Patterns ◽  
Quenching Method ◽  
Co Doped

Tellurite glasses of varying Er3+/Nd3+ concentration were successfully prepared by melt-quenching method. The X-Ray diffraction pattern was determined by using Siemens Diffractometer D5000 while the optical properties were measured using Shimadzu 3101 pc UV-VIS NIR scanning spectrophotometer. It was found that the diffraction patterns of all samples showed glasses characteristics. The optical band gap, Eopt¬ increased proportionally with the content of Er¬2O3 but Urbach energy, ∆E decreased due to the increasing Er2O3 contents.

scholarly journals Investigation on Structure of TeO2-B2O3-SiO2-Al2O3-KF Glasses

2020 ◽  
Vol 36 (2) ◽  
Author(s):  
Phan Van Do
Keyword(s):  
Optical Band Gap ◽  
Urbach Energy ◽  
Thermal Studies ◽  
Glass Network ◽  
X Ray Diffraction ◽  
Melt Quenching ◽  
X Ray ◽  
Thermal Analyzer ◽  
Amorphous Nature ◽  
Xrd Patterns

Borotellurite glasses were prepared by melt quenching technique. Amorphous nature of samples was confirmed through X-ray diffraction (XRD) patterns. Effect of B2O3 content on the structure of glass network was studied through Fourier-transform infrared spectroscopy (FTIR) spectra. Optical band gap and Urbach energy were found from analysis of optical absorption spectra. Thermal studies were carried out by using Differential thermal analyzer (DTA) measurements.

scholarly journals Synthesis of indium oxi-sulfide films by atomic layer deposition: The essential role of plasma enhancement

2013 ◽  
Vol 4 ◽  
pp. 750-757 ◽  
Author(s):  
Cathy Bugot ◽  
Nathanaëlle Schneider ◽  
Daniel Lincot ◽  
Frédérique Donsanti
Keyword(s):  
Atomic Layer Deposition ◽  
Optical Band Gap ◽  
Atomic Layer ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Growth Cycles ◽  
X Ray ◽  
Layer Deposition ◽  
Plasma Enhancement

This paper describes the atomic layer deposition of In2(S,O)3 films by using In(acac)3 (acac = acetylacetonate), H2S and either H2O or O2 plasma as oxygen sources. First, the growth of pure In2S3 films was studied in order to better understand the influence of the oxygen pulses. X-Ray diffraction measurements, optical analysis and energy dispersive X-ray spectroscopy were performed to characterize the samples. When H2O was used as the oxygen source, the films have structural and optical properties, and the atomic composition of pure In2S3. No pure In2O3 films could be grown by using H2O or O2 plasma. However, In2(S,O)3 films could be successfully grown by using O2 plasma as oxygen source at a deposition temperature of T = 160 °C, because of an exchange reaction between S and O atoms. By adjusting the number of In2O3 growth cycles in relation to the number of In2S3 growth cycles, the optical band gap of the resulting thin films could be tuned.

scholarly journals Optical and thermal properties of TeO2–B2O3–Gd2O3 glass systems

2019 ◽  
Vol 37 (4) ◽  
pp. 517-525
Author(s):  
C. Eevon ◽  
M.K. Halimah ◽  
M.N. Azlan ◽  
R. El-Mallawany ◽  
S.L. Hii
Keyword(s):  
Thermal Properties ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Glass Network ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Nature ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

AbstractNew glass samples with composition (1 – x)[(TeO2)70(B2O3)30] – x(Gd2O3) with x = 0.2, 0.4, 0.6, 0.8 and 1.0 in mol% have been synthesized by conventional melt-quenching techniques. X-ray diffraction (XRD) studies were performed in order to confirm the amorphous nature of the samples. The density of the samples has been found to vary with the Gd2O3 content, whereas an opposite trend has been observed in the molar volume. The analysis of Fourier Transform Infrared (FT-IR) spectroscopy of the samples showed that the glass network is mainly built of TeO3, TeO4, BO3 and BO4 units. The addition of Gd2O3 changed the refractive index, optical band gap and Urbach energy of the glass samples. The thermal properties of the studied glasses were investigated by measuring the thermal diffusivity of the samples by using photoflash method at room temperature.

Structural, Electrical and Dielectric Properties of DC Reactive Magnetron Sputtered ZrO2 Films for Metal-Oxide-Semiconductor Devices

2014 ◽  
Vol 781 ◽  
pp. 155-165
Author(s):  
P. Kondaiah ◽  
S. Uthanna
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Optical Band Gap ◽  
Spectroscopic Studies ◽  
Oxide Semiconductor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Partial Pressures ◽  
Electrical And Dielectric Properties ◽  
Metallic Target

Thin films of zirconium oxide (ZrO2) were deposited by DC magnetron sputtering of metallic target of zirconium on to quartz and p-Si (100) substrates at various oxygen partial pressures in the range 2x10-2 - 6x10-2 Pa. The crystallinity, surface morphology and optical absorption of the films were influenced by the oxygen partial pressure. X-ray photoelectron spectroscopic studies revealed that the films formed at oxygen partial pressure of 4x10-2 Pa were of stoichiometric ZrO2. X-ray diffraction profiles indicated that the grown films were of nanocrystalline with crystallite size increased from 5 nm to 9 nm with increase of oxygen partial pressure from 2x10-2 Pa to 6x10-2 Pa. The optical band gap of the films increased from 5.65 to 5.80 eV and the refractive index increased from 2.02 to 2.08 with the increase of oxygen partial pressure from 2x10-2 to 6x10-2 Pa respectively. The fabricated MOS structure with the configuration of Al/ZrO2/p-Si showed the dielectric constant of 22 and leakage current density of 1x10-6 A/cm2.

Effect of Dysprosium Nanoparticles on the Optical Properties of Zinc Borotellurite Glass Systems

2017 ◽  
Vol 268 ◽  
pp. 13-17 ◽  
Author(s):  
M.N. Ami Hazlin ◽  
Mohamed Kamari Halimah ◽  
Farah Diana Mohammad ◽  
M.F. Faznny ◽  
Shahrim Mustafa Iskandar
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Molar Fraction ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Amorphous Nature

The glass samples of zinc borotellurite glass doped with dysprosium nanoparticles with chemical formula TeO20.7B2O30.30.7ZnO0.31-xDy2O3x (where x= 0.01, 0.02, 0.03, 0.04 and 0.05 molar fraction) have been fabricated by using melt quenching technique. In this study, the structural and optical properties of the zinc borotellurite glass doped with dysprosium nanoparticles were characterized by using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and UV-Vis spectroscopy. From the XRD, the amorphous nature of the glass samples has been confirmed. The infrared spectra revealed four obvious bands which are assigned for BO3, BO4 and TeO4 vibrational groups. The direct and indirect optical band gap, as well as Urbach energy, was calculated through absorption spectra obtained from UV-Vis spectroscopy. From the spectra, it is observed that both direct and indirect optical band gap decreases as the concentration of dysprosium nanoparticles increase. Other than that, the Urbach energy is observed to have an inverse trend with the optical band gap. The Urbach energy is increases as the concentration of dysprosium nanoparticles increases.

Role of the Structure and Electronic Properties of Fe2O3-MoO3 Catalyst on the Dehydration of Isopropyl Alcohol

1993 ◽  
Vol 58 (7) ◽  
pp. 1591-1599 ◽  
Author(s):  
Abd El-Aziz A. Said
Keyword(s):  
Active Sites ◽  
Isopropyl Alcohol ◽  
Oxide Catalyst ◽  
Flow System ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalyst Composition ◽  
Surface Active

Molybdenum oxide catalyst doped or mixed with (1 - 50) mole % Fe3+ ions were prepared. The structure of the original samples and the samples calcined at 400 °C were characterized using DTA, X-ray diffraction and IR spectra. Measurements of the electrical conductivity of calcined samples with and without isopropyl alcohol revealed that the conductance increases on increasing the content of Fe3+ ions up to 50 mole %. The activation energies of charge carriers were determined in presence and absence of the alcohol. The catalytic dehydration of isopropyl alcohol was carried out at 250 °C using a flow system. The results obtained showed that the doped or mixed catalysts are active and selective towards propene formation. However, the catalyst containing 40 mole % Fe3+ ions exhibited the highest activity and selectivity. Correlations were attempted to the catalyst composition with their electronic and catalytic properties. Probable mechanism for the dehydration process is proposed in terms of surface active sites.

scholarly journals Modeling of magneto-conductivity of bismuth selenide: a topological insulator

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Yogesh Kumar ◽  
Rabia Sultana ◽  
Prince Sharma ◽  
V. P. S. Awana
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Single Crystal ◽  
Single Crystals ◽  
X Ray Diffraction ◽  
Field Range ◽  
X Ray ◽  
Bulk Carriers ◽  
Different Temperatures

AbstractWe report the magneto-conductivity analysis of Bi2Se3 single crystal at different temperatures in a magnetic field range of ± 14 T. The single crystals are grown by the self-flux method and characterized through X-ray diffraction, Scanning Electron Microscopy, and Raman Spectroscopy. The single crystals show magnetoresistance (MR%) of around 380% at a magnetic field of 14 T and a temperature of 5 K. The Hikami–Larkin–Nagaoka (HLN) equation has been used to fit the magneto-conductivity (MC) data. However, the HLN fitted curve deviates at higher magnetic fields above 1 T, suggesting that the role of surface-driven conductivity suppresses with an increasing magnetic field. This article proposes a speculative model comprising of surface-driven HLN and added quantum diffusive and bulk carriers-driven classical terms. The model successfully explains the MC of the Bi2Se3 single crystal at various temperatures (5–200 K) and applied magnetic fields (up to 14 T).

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