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Characterization, optical and luminescence features of cobalt ions in multi-component PbO Al2O3TeO2GeO2SiO2 glass ceramics
摘要： Glass ceramics of the composition PbOeAl2O3eTeO2eGeO2eSiO2 doped with CoO (ranging between 0 and 1.0 mol %) were prepared by melt quenching technique followed by heat treatment. The techniques such as XRD, SEM, EDS and DTA were employed for the characterization of the prepared samples. Conventional spectroscopic studies viz., optical absorption, photoluminescence, FTIR and Raman were also performed on these samples. The optical absorption spectra of the titled glass ceramics exhibited two principal absorption bands, one at about 594 nm and the second one consisting of multiplets with the meta centre at about 1455 nm ascribed to the 4A2 (4F) → 4T1 (4P) and 4A2 (4F) → 4T1 (4F) transitions of tetrahedrally coordinated Co2+ ions, respectively. Besides these, the spectra also exhibited two feeble bands at about 532 and 643 nm which are the characteristics of octahedrally coordinated Co2+ and Co3+ ions, respectively. Using Tanabe Sugano diagram the crystal field splitting parameter Dq, Racah parameters B, C and nephelauxetic ratio, β were evaluated for Co2+ ions. The photoluminescence spectra of the titled glass ceramics have exhibited two broad emission bands at 628 and 870 nm ascribed to 4T1 (4P) → 4A2 (4F) and 4T1 (4P) → 4T2 (4F) tetrahedral transitions of Co2+ ions, respectively. FTIR and Raman spectra of the titled samples exhibited various asymmetrical and symmetrical vibrational bands due to viz., silicate, germanate, PbO4, PbO6, AlO6, TeO4, TeO3 and CoIIIeO vibrations in the glass ceramic matrix. The spectroscopic investigations on the titled glass ceramics have revealed that if CoO is present in small quantities the cobalt ions predominantly occupy the octahedral sites in the glass network, whereas the tetrahedrally coordinated Co2+ ions are found to increase if the concentration of nucleating agent CoO is gradually increased up to 1.0 mol%. As a result the degree of depolymerization of the glass network decreases which in turn enhances its rigidity with increasing the concentration of nucleating agent CoO. From these investigations we report that the glass ceramics doped with 1.0 mol% of CoO are suitable for insulating devices as well as for photonic devices.
关键词： Photoluminescence,Raman spectra,XRD,Multi-component glass ceramics,SEM,Optical absorption,Cobalt ions
更新于2025-09-23 15:23:52
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Characterization and thermoluminescence behavior of beta irradiated NaBaBO3 phosphor synthesized by combustion method
摘要： NaBaBO3 host material was synthesized using the combustion method. In order to optimize the performance of the material, effects of sintering temperatures varying from 600 to 1000 °C were investigated. The sintering temperature and dwell time were found to have pronounced effects on the pure NaBaBO3 material. X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) techniques were used to confirm the phase formation and examine the surface morphology of the prepared powder material, respectively. TL behavior of NaBaBO3 was studied at various beta doses. It is seen that the sample exhibits well resolved TL glow peak at a peak temperature about 175 °C and corresponding TL intensity increases with the increasing beta dose. However, TL glow peak slightly shifts to lower temperature with the increasing beta dose level. This is the first TL report of a phosphor with a NaBaBO3 host. The TL kinetic parameters were estimated by the peak shape (PS) method and CGCD software. TL glow curves of NaBaBO3 consist of several traps and exhibited second order kinetics. A possible TL mechanism was also discussed using the energy level model. The obtained results can provide valuable knowledge related to the investigation of the intrinsic nature characteristics of NaBaBO3 in research fields pertaining to dosimetry.
关键词： TLanal software,XRD,Peak shape method,NaBaBO3,Thermoluminescence,SEM
更新于2025-09-23 15:23:52
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Cs/MAPbI3 composite formation and its influence on optical properties
摘要： The stability issue is very critical for organic hybrid perovskite CH3NH3PbI3 to be used in solar cell applications; whereas CsPbI3 is reported to be more stable than that of CH3NH3PbI3. In the present work, we attempt to substitute Cs+ in the organic hybrid perovskite CH3NH3PbI3 matrix to form Csx(CH3NH3)1-xPbI3 with 0 ≤ x ≤ 0.4 in ambient conditions i.e., at room temperature and in air via solid state reaction route. The structural studies reveal presence of both CH3NH3PbI3 (tetragonal, I4/mcm) and CsPbI3 (orthorhombic, Pnma) phases for x > 0. It is appearing that partial solid solution formation has occurred up to x = 0.2 but for x > 0.2, the composite formation dominates. The optical band gap is slightly increased by ~ 0.02 eV with substitution. These compounds keep the basic feature of parent CH3NH3PbI3 along with stability of CsPbI3.
关键词： Composite,Raman,Perovskite materials,XRD
更新于2025-09-23 15:23:52
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Synthesis and characterization of novel imine substituted phthalocyanine for sensing of l-cysteine
摘要： New mono-nuclear cobalt (II) tetra[4-(2-{(E)-[(4-bromophenyl)imino]methyl}phenoxy)] phthalocyanine (CoTBrImPc) complex has been synthesized for the first time in pure state. The synthesized dark blue coloured complex was characterized by elemental analysis, IR, UV-Vis, NMR, Mass, powder X-ray diffraction and thermogravimetric analysis (TGA) to understand the structural integrity, purity and crystalline property of the complex. The synthesized phthalocyanine complex was found to be electrochemically active and it was immobilized on the glassy carbon electrode by drop-casting method and used for the detection of L-cysteine. The CoTBrImPc modified electrode was found to be a good electrocatalyst for the catalytic oxidation of L-cysteine with shift in the overpotential towards less positive potential and an increase in the catalytic current compared to bare glassy carbon electrode (GCE). The linear response was observed for the voltametric detection of L-cysteine in the concentration range 10-100 nM with coefficient of regression R2= 0.9993 and LOD of 3 nM and sensitivity of 2.99 μA nM-1 cm-2. The amperometric sensor was also developed for the detection of L-cysteine which showed linear response in the concentration range same as that of cyclic voltammertry technique with a linear equation y = 0.7582x+16.9535 and correlation coefficient of R2= 0.9961. The LOD and LOQ values for amperometric detection were 4 nM and 12 nM, respectively with the sensitivity value of 10.81 μA nM cm-2.
关键词： TGA,L-cysteine,XRD,Amperometry.,Phthalocyanine,cyclic voltammetry
更新于2025-09-23 15:23:52
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[Advances in Intelligent Systems and Computing] Information Systems Design and Intelligent Applications Volume 862 (Proceedings of Fifth International Conference INDIA 2018 Volume 1) || Study of Electrical and Magnetic Properties of Multiferroic Composite (BiFeO3)x(Ba5RTi3V7O30)1?x
摘要： Polycrystalline Samples of the composite (BiFeO3)x(Ba5RTi3V2O30)1?x (R––Rare Earth Element) is prepared by high-temperature Solid-State Reaction Technique. The formation of the material has been con?rmed through XRD (X-ray Diffractometer) to ensure the single-phase formation. Dielectric characterization has been done by Impedance Analyser (HIOKI-IM3536) to study the variation of dielectric constant with frequency and temperature in a wide range to see the dielectric anomaly. Magnetization study is also done by Vibration Magnetometer for different values of x in the composite (BiFeO3)x(Ba5RTi3V2O30)1?x.
关键词： Dielectric,XRD,Impedance analyzer,magnetization,Neel temperature
更新于2025-09-23 15:23:52
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Electronic mobility and crystal structures of 2,5-dimethylanilinium triiodide and tin-based organic-inorganic hybrid compounds
摘要： We synthesize single crystals of a new 2,5-dimethylanilinium tin iodide organic-inorganic hybrid compound and 2,5-dimethylanilinium triiodide. Single-crystal X-ray diffraction reveals that the hybrid grows as a unique rhombohedral structure consisting of one-dimensional chains of SnI6-octahedra that share corners and edges to build up a ribbon along the [111] direction. Notably, we find that hypophosphorous acid, H3PO2, is of central importance to the formation of this hybrid. In the absence of H3PO2, we synthesize 2,5-dimethylanilinium triiodide from the same starting compounds. We investigate the synthesis routes that drive the growth of these two compounds with distinct crystal structures, appearance and properties. Pulse-radiolysis time-resolved microwave conductivity measurements and density functional theory calculations reveal that both compounds have low charge carrier mobilities and very long lifetimes, consistent with their one-dimensional structural characteristics. Our findings give a better understanding of the relation between synthesis, crystal structures and charge carrier mobilities.
关键词： Tin iodide,Single-crystal XRD,Organic-organic hybrids,Microwave conductivity,Hypophosphorous acid,Triiodide
更新于2025-09-23 15:23:52
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Ion beam measurements for the investigation of TiN thin films deposited on different substrates by vacuum arc discharge
摘要： Titanium nitride thin films were deposited on different substrates using vacuum arc discharge system. Simultaneous ion beam analysis measurements including elastic backscattering (EBS) and nuclear reaction analysis (NRA); were applied for both composition analysis and thickness measurements of the prepared TiN films. Experimental conditions have been optimized to avoid overlapping of peaks of different nuclear reactions products, especially those related to interaction between ion beam and light elements present in totally different substrates. Independent compliment measurements utilizing time-of-flight elastic recoil detection analysis (TOF-ERDA), scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD) measurements were also applied to verify the experimental findings obtained by EBS and NRA measurements. The results have shown that all prepared TiN films have N/Ti ratio of around 1, with low levels of contamination elements.
关键词： IBA,TiN film,XRD,Substrates,SEM/EDX,Vacuum arc discharge
更新于2025-09-23 15:23:52
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Investigations on the quantum chemical studies and physico-chemical properties of an opto-electronic material 1-Allyl-2-Aminopyridine-1-ium bromide
摘要： In the present work, the dual approach of quantum chemical studies and experimental characterizations of the title compound 1-Allyl-2-Aminopyridine-1-ium bromide (1A2APB) were carried out for the first time. The molecular geometry of 1A2APB was optimized by density functional theory (DFT) using B3LYP/6-311++G (d,p) basis set. The optimized geometric structural parameters were compared with the experimental findings and discussed. The dipole moment (μ) and first hyperpolarizability (β) were calculated to predict the NLO behavior. The frontier molecular orbital (FMO), molecular electrostatic potential (MESP), Mulliken atomic charge and thermodynamic properties were investigated to get a better insight of the molecular properties. Stability of the compound arising from hyper-conjugative interactions, intra-molecule re-hybridization and charge delocalization within the molecule were analyzed using NBO analysis. Further, 1A2APB was synthesized and good quality single crystals were grown by slow evaporation technique. Studies such as microanalysis and powder XRD were performed to ascertain material composition and phase respectively. The various characteristic functional groups were identified through FT-IR spectroscopic analyses. The NLO efficiency was measured to be about greater than 5 times that of standard KDP. Thermal behaviors were explored by the simultaneous TG/DTA-DSC thermograms. The UV–Vis–NIR spectral data and fluorescence spectrum were recorded to explore the optical transmission and emission properties respectively. The dielectric properties were evaluated as a function of frequency at various temperatures. The photoconducting nature was analyzed through photoconductivity measurement. The Vicker’s microhardness test was performed at room temperature from which the mechanical stability was analyzed through the classical Meyer’s relation.
关键词： Photoconductivity,Powder XRD analysis,DFT calculations,Organic materials,Non-linear optics,Crystal growth
更新于2025-09-23 15:23:52
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Determination of physical properties of graphene doped ZnO (ZnO:Gr) nanocomposite thin films deposited by a thermionic vacuum arc technique
摘要： This study is focused on the growth of graphene doped ZnO (ZnO:Gr) nanocomposite thin films by a thermionic vacuum arc (TVA) technique. ZnO:Gr nanocomposite thin films were deposited onto glass and silicon (Si) substrates. The influence of the dopant effect on structural, optical, morphological properties of the ZnO:Gr nanocomposite thin films were investigated by using various analysis techniques such as interferometer, UV-Visible spectrophotometer, X-ray diffraction (XRD), Raman spectrometer, Fourier Transform Infrared spectroscopy (FTIR), Photoluminescence (PL) spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), and Atomic Force Microscopy (AFM). Thicknesses value of ZnO:Gr nanocomposite thin films for the deposited layers onto glass and Si substrates were measured as to be 50 nm and 20 nm, respectively. In XRD patterns, the reflections of the ZnO and carbon nanostructures were observed. Using UV–Vis spectrophotometer and optical interferometer, the refractive index, reflectance, transmittance, absorbance and optical band gap graphs of the ZnO:Gr nanocomposite thin films were determined. Optical band gap of the ZnO:Gr nanocomposite thin film that deposited on glass substrate was determined as to be 3.15 eV via optical method and the result is in good harmony with PL measurement. PL spectrum showed an ultraviolet (UV) emission peak at 397 nm (3.12 eV). From the Raman analysis of the ZnO:Gr nanocomposite thin films, ZnO, D and 2D peaks of the graphene were observed. FTIR spectroscopy was used to analyze the chemical composition of the samples. According to AFM and FESEM analysis, ZnO:Gr nanocomposite thin films are smooth, flat, granular, uniform and dense form. Due to the larger crystallite sizes ZnO:Gr nanocomposite thin film onto Si substrate has lower resistivity according to the ZnO:Gr nanocomposite thin film deposited onto glass substrate. As a result, ZnO:Gr nanocomposite thin films are promising material for potential applications as to be a transparent conducting oxide (TCO) material.
关键词： FESEM,TVA,ZnO:Gr nanocomposite thin films,XRD,AFM
更新于2025-09-23 15:23:52
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Systematic investigations on the effect of prolong UV illumination on optoelectronic properties of ZnO honeycomb nanostructures
摘要： Herein, the effect of prolong UV illumination over ZnO optoelectronic characteristics has been investigated. The photoluminescence analysis has shown significant enhancement in deep level emission (DLE) after sample being exposed to UV radiations. The formation of photo-induced oxygen vacancies (VO) over the ZnO surface was found to be responsible for such noteworthy enhancement in DLE. The observed phenomenon was further utilized for controlled incorporation of VO in ZnO via UV illumination, towards obtaining optimal device performance. The UV treated photo-detector has shown significantly high photo-responsivity and photo-sensitivity in the deep UV region.
关键词： Zinc oxide,Honeycomb structure,Deep UV photodetector,XRD,Lattice defects
更新于2025-09-23 15:23:52