Influence of Mg doping on the structural,optical, and electrical properties of Zn0.95Li0.05O Nanoparticles

This study investigates the effect of Li and Mg codoping on the structural, optical, and electrical properties of the ZnO. Zn_0.95−xLi_0.05Mg_xO (x = 0.00, 0.01, 0.02, 0.03) nanoparticles are synthesized by hydrothermal method. X-ray diffraction (XRD) results confirmed that all samples are polycrystalline with a hexagonal-wurtzite structure. The surface morphology of the samples were examined by Scanning Electron Microscopy (SEM). The SEM analysis showed that all samples exhibit cheese-like plates and the plate sizes increase with Mg addition. Optical properties were examined by UV-VIS diffuse reflectance spectroscopy. The optical measurements indicate that the reflectance edge of the samples have red shift up to 2% Mg doping level, but blue-shift for 3% Mg doping. The optical band gap of Zn_0.95−xLi_0.05Mg_xO nanostructures are calculated as 3.227, 3.214, 3.209, and 3.221 eV with x = 0.00, 0.01, 0.02, 0.03 respectively. Electrical properties including the carrier concentration, Hall mobility, and resistivity were studied using Van-der Pauw method. The temperature resistivity curves of the samples shown typical semiconductor behavior. The carrier concentration decreases with increasing doping level up to 2% Mg, and it slightly increases for 3% Mg. The variation of the Hall mobility for the samples is inversely proportional to the carrier concentration.     

Influence of cerium doping concentration on the optical properties of Ce,Mg:LuAG scintillation ceramics

Ce,Mg:LuAG scintillation ceramics with Ce dopant content ranging from 0.025?at.% to 0.3?at.% and constant 0.2?at.% Mg codoping were fabricated by solid-state reaction. The effects of Ce concentration and annealing conditions on the microstructure, optical quality and scintillation properties are studied in great details. Lattice parameters as well as the absorption, photoluminescence, radioluminescence and thermoluminescence characteristics are investigated as a function of Ce content. Both the photoluminescence and scintillation decays are measured as well in order to study re-absorption and concentration quenching processes. In addition, an enhanced positive effect of air annealing on radioluminescence intensity and light yield is put in evidence. Moreover, the role of the charge transfer absorption of Ce⁴⁺ is investigated. Thermoluminescence measurements are performed to investigate the influence of both air annealing and Ce concentration on defects acting as traps. Finally, the correlations among steady state scintillation efficiency, light yield, thermoluminescence and Ce³⁺ concentration are found and discussed.     

Surfactant effects on structural,optical and morphological characteristics of microwave irradiated CdO nanostructures

Surfactant based microwave irradiated and alkaline medium involving wet chemical method was adopted to prepare CdO nanostructures. The phase evaluation of prepared and annealed CdO nanostrucutures has been analyzed by XRD and FTIR. The average size of the crystallite was estimated to be 54 nm for the NH₄OH reagent and 60 nm for the NaOH reagent in the assisted synthesis. Specific surface area, lattice parameter, X-ray density, dislocation density, microstrain, texture coefficient and Williamson Hall have been calculated from the XRD profile. UV transmittance and the K-M plot of DRS and PL spectra were used to examine the optical properties of CdO nanostructures. The spherical and rod-like structures of CdO prepared with strong and weak alkaline medium have been recorded through SEM and TEM micrographs. The four-step process of hydration, intermediate formation, metal hydroxide formation, and metal oxide formation confirms that the experiment in the presence of 0.1 M sodium hydroxide results in rod-shaped nanostructures.     

Structural,optical, morphological and electrochemical properties of ZnO and graphene oxide blended ZnO nanocomposites

A simple cost-effective co-precipitation method was adopted to prepare ZnO nanoparticles from a metal organic framework. The synthesized ZnO nanoparticles were blended with graphene oxide (GO) to prepare the ZnO-GO nanocomposite. The physicochemical properties of ZnO nanoparticles and ZnO-GO nanocomposite were analyzed via various techniques. The structural behavior of ZnO and ZnO-GO nanocomposite was studied by XRD and FT-IR analysis. The XRD profile confirms the hexagonal structure with an average crystallite size of 19.4 nm for ZnO and 16.2 nm for ZnO-GO nanocomposites. The functional groups and the vibration modes of the samples were examined through FT-IR. It confirms the metallic presence in the ZnO and ZnO-GO samples in the wavenumber range of 400–600 cm^?1. The optical properties of ZnO and ZnO-GO were studied via UV–vis spectra. The surface morphology of the samples was recorded through FESEM, and the elemental presence in the samples was examined by EDX. It confirms that the prepared samples are spherical in shape with uniform size distributions. Cyclic voltammetry has been used to study the redox behavior of electroactive ZnO and ZnO-GO composites.     

Influence of yttrium doping on the structural,morphological and optical properties of nanostructured ZnO thin films grown by spray pyrolysis

This study reports on the deposition of highly transparent, n-type ZnO thin films on glass substrate at 450?°C using spray pyrolysis processing, with the simultaneous insertion of yttrium (Y) at different percentages (0, 2, 5, 7?at%) as a dopant. The effect of Y doping on the structure, morphology and optical properties of Y doped ZnO (ZnO:Y) was investigated for optoelectronic applications. The obtained thin films were characterized by means of X-ray diffraction, field-emission scanning electron microscopy (FESEM), UV–visible absorbance measurements, photoluminescence (PL) and cathodoluminescence (CL) spectroscopy. The as-prepared films exhibit well-defined hexagonal wurtzite structure grown along [002]. Field emission scanning electron microscope micrographs of the pure ZnO and ZnO:Y showed that the films acquired a dominance of hexagonal-like grains, the morphology was influenced by Y incorporation. All the films showed high transparency in the visible domain with an average transmittance of 83%. The band gap energy, E_g, increased from 3.12?eV to 3.18?eV by increasing the Y doping concentration up to 5?at% and then decreased to 3.15?eV for 7?at% Y content. The PL and CL measurements reveal a strong ultraviolet (UV) emission, suggesting that the as-prepared ZnO:Y thin films can potentially be used in optoelectronic devices.     

Hydrothermal synthesis of Li co-doped Zn0.98Mg0.02O nanoparticles and their structural,optical and electrical properties

Zn_0.98−xMg_0.02Li_xO (x=0.0, 0.01, 0.02, 0.03) nanoparticles were synthesized by the hydrothermal method. The structural, optical and electrical properties of the samples were analyzed by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Diffuse Reflectance UV–vis spectroscopy, and Hall effect measurements. XRD results showed that Zn_0.98−xMg_0.02Li_xO with wurtzite structure are obtained without impurities and additional phases. The lattice parameters (a, c) initially decrease, but they increase with further Li doping. The optical measurements exhibited blue-shift of optical band edge and widening of the band gap. Temperature dependent transport measurements using Van der Pauw method showed that Li doping increased the resistivities and charge carrier density, while it decreased the Hall mobility.     

Influence of Co concentration on the structural,optical, morphological and photo-diode properties of cerium oxide thin films

Highly uniform and well-dispersed ring shaped particles of CDC (Cobalt doped cerium oxide) films are successfully deposited by Nebulizer Spray Pyrolysis (NSP) technique. The structural, morphological, optical and photo-diode properties of the films are investigated. Cubic fluorite crystallites are detected by X-ray diffraction pattern with preferred orientation along (111) direction. Co concentrations distress the crystallinity and structural parameters. The transmittance decreases with increasing Co concentration due to the presence of covalent bonds between cerium and oxygen. PL spectra revealed that three consistent sharp and broad peaks observed at 369 (3.31 eV), 394 (3.14 eV) and 425 nm (2.91 eV) correspond to near-band-edge emission (NBE) in UV region, deep level emission (DLE) in violet and blue of the visible region respectively. The deep level emissions result from the recombination of electrons with holes trapped in singly ionized oxygen vacancies (Vo+). Large agglomerated ring, button and spherical crystallites are obtained with the typical size in the range 83–207 nm. XPS analysis exhibits the presence of Ce, Co, O, C and Na in the films that indicates the non-stoichiometric behavior. I-V characteristics show the rectifying nature with a typical forward to reverse current ratio of ~7 in the range −4 to +4 V. The turn-on voltage of the hetero-junction is found to be ~1.7 V. The transient photocurrent behavior indicates that the device has a good stability and quick response to suggests that the prepared heterojunction device can be used as a white light photodetector and UV detector applications.     

Camphor sulfonic acid doped polyaniline-tin oxide hybrid nanocomposites: Synthesis,structural, morphological,optical and electrical transport properties

Camphor sulfonic acid (CSA) doped PANi–SnO₂ hybrid nanocomposites were synthesized by solid-state synthesis route with varying amounts (10–50%) of CSA. X-ray diffraction studies have proven the successful incorporation of CSA into the polyaniline–SnO₂ hybrid nanocomposites and the results are also supported by microstructural analysis. UV–visible and Fourier infrared spectroscopy studies have provided insight into the electronic interaction between the CSA, polyaniline, and SnO₂. The room temperature dc electrical conductivity of CSA-doped PANi–SnO₂ hybrid nanocomposite films were observed to depend on the amount of CSA doping and the morphology.     

Effects of nanoparticle size and concentration on optical,toughness, and thermal properties of polycarbonate

The influences of size and content of silicon dioxide (SiO₂) nanoparticles on the morphological, optical, toughness, and thermal properties of polycarbonate (PC) were investigated. The PC nanocomposites were prepared using a twin-screw extruder followed by injection molding. The scanning electron microscope (SEM) micrographs displayed an adequate level of nano-SiO₂ particle distribution within the PC matrix but still revealed some agglomerated particles. Upon increasing the content of nanoparticles, slightly larger agglomerates formed. These agglomerated particles caused a reduction in material transparency due to light loss via reflection and scattering. However, the incorporation of nano-SiO₂ into the PC matrix greatly improved toughness properties and slightly increased glass-transition temperature (T_g), in conjunction with filler content (up to 4 vol %). This was particularly in the case with the smaller sized nano-SiO₂, which not only significantly improved toughness but also enhanced optical properties of the PC nanocomposites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47634.     

Effect of doping and changing of the annealing temperature on the structural and optical properties of ZnS

Nano ZnS doped with Co, Mn, or Fe have been synthesized via thermolysis technique at different annealing temperatures (300, 400, and 500°C). The effect of doping and annealing temperature on the lattice parameter and crystalline size of ZnS are studied in detail by Rietveld refinement method of X-ray diffraction data. To confirm the formation of a zinc blend structure of annealed and doped ZnS, Fourier-transform infrared are investigated. The energy gaps of doped and annealed ZnS are determined using ultraviolet spectroscopy technique. Undoped and doped ZnS with Fe emitted violet, blue, and green colors depend on the annealing temperature. Moreover, Mn-doped ZnS exhibits blue-green emission, while Co-doped ZnS has a blue emission only.     

Synthesis,structural, linear and nonlinear optical properties of chromium doped SnO2 thin films

The present work concentrates on some physical investigation of the undoped and Cr doped SnO₂ thin films deposited onto precleaned glass substrates by the spray pyrolysis system. The physical properties of the undoped and Cr doped SnO₂ thin films were investigated by the X-ray diffraction (XRD), atomic force electron microscope (AFM), field emission scanning electron microscope (FESEM), four-probe method and double beam spectrophotometer. The undoped and Cr doped SnO₂ films display a polycrystalline nature with orthorhombic crystal structure. The linear optical constants energy gap E_g, refractive index n, absorption coefficient α, static refractive index n_o, oscillation energy E_o, dispersion energy E_d and the Urbach energy of the undoped and Cr doped SnO₂ thin films were evaluated. The investigated films exhibit a direct energy gap and their values decrease with the increasing of Cr doping content while the Urbach energy follows a reverse behavior. On the other hand, the nonlinear optical constants (third-order nonlinear susceptibility ${\mathit{\chi }}^{(3)}$ and nonlinear refractive index n₂) have been increased with increasing the Cr doping content. Finally, it has been found that the sheet resistance and conductivity of the synthesized thin films were enhanced by increasing the Cr doping content. The 5?wt% Cr doped SnO₂ thin film has a high value of the figure of merit among other films.     

Role of tellurium addition on the linear and non-linear optical,structural, morphological properties of Ag60-xSe40Tex thin films for nonlinear applications

The tellurium (Te)-doped Ag_60-xSe₄₀Te_x (x = 0%, 5%, 10%, 15%) thin films of thickness ∼800 nm were prepared from the bulk sample by thermal evaporation method on a glass substrate. The X-ray diffraction study revealed the amorphous nature of the films whereas the change in vibrational modes was noticed from the Raman spectroscopy. The composition of the films was verified by energy dispersive X-ray analysis and the surface morphology pictures were taken by field emission scanning electron microscopy and atomic force microscope. The changes in optical properties (linear and non-linear) with Te addition were studied from UV-Visible spectroscopy data and related empirical formulas. The addition of Te reduced the bandgap values significantly and the reduction in transmission resulted in the increase of the linear refractive index. The decrease in optical bandgap is due to an increase in disorder while the width of the tail in the gap increased with Te%. The optical density, dispersion energy, extinction coefficient, carrier concentration, dielectric constant, oscillator wavelength increased while the oscillator energy, oscillator strength, optical electronegativity decreased with Te content. The electrical susceptibility increased with Te content. The non-linear susceptibilities and the non-linear refractive index increased which is good for the nonlinear photonic devices.     

The role of Pb and annealing temperature on the structural,magnetic, optical and dielectric properties of W-type hexaferrite nanostructures

In this paper, W-type Sr_1-xPb_xCo₂Fe₁₆O₂₇ nanostructures were synthesized by auto-combustion sol-gel method. Then, the effects of annealing temperature and Pb contents on the structural, magnetic, optical, and dielectric properties of Sr_1-xPb_xCo₂Fe₁₆O₂₇ nanostructure were investigated. First, a gel of metal nitrates with a specific molar ratio with x different was prepared and then the gel was annealed at different temperatures for 4?h. To determine the annealing temperature of the samples, the prepared gel was examined by thermogravimetric analysis and differential thermal analysis. The morphology and crystal structure of the prepared samples were characterized by field emission scanning electron microscopy (FESEM) and X-ray diffraction pattern (XRD). The results of XRD patterns indicated that the annealing temperature of synthesized Sr_1-xPb_xCo₂Fe₁₆O₂₇ was reduced by increasing Pb contents. In addition, FESEM images showed that the microstructure of the samples was homogeneous and uniform, but since the samples have a magnetic property, the particles were aggregated. Fourier transform infrared analysis (FT-IR) was used to confirm the phase formation. The FT-IR results of the samples indicated that the tetrahedral and octahedral sites, which are the important attributes of hexaferrites, were formed. The magnetic properties of the samples were measured by vibrating sample magnetometer (VSM). The VSM results of the samples showed that because of increasing Pb content, the amount of saturation magnetization and that of magnetic coercivity decreased from 81.29 to 10.23?emu/g and 2285–477?Oe, respectively. The optical properties of the samples were investigated by ultraviolet–visible spectroscopy, which revealed that the energy gap decreases and the absorption peaks move towards longer wavelengths by increasing Pb content. The dielectric properties of the samples were investigated by the LCR meter. It was found that by increasing frequency, the dielectric constant (ε^′) and the dielectric loss (?) of the samples were decreased.     

Effects of sintering process on the structural,dielectric, and optical absorption properties of KNbO3-based ceramics

The influence of the sintering temperature and the dwell time on the structural, optical, and dielectric properties of [KNbO₃]_0.8[Ba(Ni_0.5Nb_0.5)O_3−δ]_0.2 ceramics (KBNNO) was systematically investigated. X-ray diffraction measurements of the ceramic bodies sintered at different temperatures indicated that all samples presented a cubic-like structure. However, the results remarkably revealed that both the sintering temperature and the dwell time are crucial factors that must be taken into account for “tuning” the optical response of the KBNNO ceramics. It was concluded that fine distortions in the (Nb,Ni)O₆ octahedral site, induced by sintering temperature and dwell time, promoted subtle changes in the local crystal field and, consequently, in the optical properties of the KBNNO. The mechanisms responsible for the observed spectral features of KBNNO were discussed by considering absorbance spectra of NiNb₂O₆ ceramics and allowed ligand-field transitions. The comparison between both optical spectra revealed a notable similarity between them. Since the octahedral site in KBNNO is equivalent to the nickel columbite structure, it was inferred that the spectral behavior is mainly driven by the same two contributions: one major associated to a distorted octahedral configuration and one minor related to spin-orbit coupling effects. In accordance with X-ray diffraction data, the temperature dependence of the dielectric properties corroborated that the KBNNO present a cubic-like phase in the whole temperature range investigated.     

Nano structured CdO films grown by the SILAR method: Influence of silver-doping on the morphological,structural and optical properties

Cadmium oxide films with and without silver-doping have been prepared by the SILAR method onto soda-lime-silica glass slides and characterized by scanning electron microscopy, UV-Visible spectroscopy and X-ray diffraction measurements. Scanning electron microscopy images show that increasing silver concentration contributed to adjust surface properties and led to a decrease in particle size from the UV-Visible spectroscopy analysis it was found that the optical band gap value of the films is increased with silver doping.     

Influence of molybdenum oxide on structural,optical and physical properties of oxychloride glasses for nonlinear optical devices

The unconventional Heavy Metal Oxide Glasses (HMOG) are characterized by a low phonon energy, large infrared range transmission, high refractive index and nonlinear optical properties. Ternary glasses have been synthesized and studied in the Sb₂O₃– MoO₃-ZnCl₂ system. Further, the glass formation compositional limits are reported and some glass samples with the formula: (90-x)Sb₂O₃ -xMoO₃–10 ZnCl₂ (10 ≤ x ≤ 50, mole%) were elaborated. Thermal properties have been measured and indicating that the glass transition temperature decreases with increasing proportions of molybdenum oxide. The evolution of density, microhardness and elastic modulus has been studied as functions of parameter x and Raman spectra measurements have been shown the partial conversion of MoO₆ octahedral units into MoO₄ tetrahedral.     

Synthesis,structural and morphological characteristics,magnetic and optical properties of Co doped ZnO nanoparticles

Zn_1−xCo_xO (x==0.05, 0.10, 0.15) nanoparticles have been synthesized by an alternative wet-chemical synthesis route using the SimAdd technique. The as-obtained powders were investigated by FT-IR spectroscopy, X-ray diffraction and thermal analysis correlated with evolved gas analysis (TG–DTA–FT-IR) in order to determine their chemical nature, crystalline structure and to establish the decomposition sequences. The precipitates are generally amorphous, but low-intensity reflection peaks assigned both to the zinc oxalate dihydrate, and zinc hydroxide can be observed in the recorded patterns, indicating that hydroxy-oxalate precipitates were obtained. The structure, morphology and magnetic properties of the thermally treated samples have been investigated by X-ray diffraction, FT-IR, HRTEM, SAED, UV–vis and EPR. XRD studies reveal a hexagonal wurtzite-type structure for all Zn_1−xCo_xO samples. TEM investigations show particle size between 28 and 37 nm, with spherical and polyhedral shapes and with tendency to form aggregates. The presence of a Co₃O₄ secondary phase was evidenced by XRD, UV–vis and EPR for the Zn_0.85Co_0.15O sample. The ferromagnetic behavior of the samples was revealed. The paper highlights that by varying the cobalt concentration it is possible to modulate the structural, morphological, optical and magnetic properties.     

Influence of grafting on structural and optical properties of nylon‐6 fibers

This study throws light on the change of the optical properties and some structural properties due to graft copolymerization of polydiallyldimethyl ammonium chloride (PDADMAC) and polyacrylamide (PAA) of nylon‐6 fibers. Multiple‐beam interferometric technique in transmission was used to study the change of the diameter, refractive indices, and birefringence of nylon‐6 fibers at different graft yields. The results were utilized to investigate the isotropic refractive index, the mean polarizabilities per unit volume, dielectric constant, dielectric susceptibility, and surface reflectivity for nylon‐6 and grafted nylon‐6 fiber. The effect of grafted PAA onto modified nylon‐6 fibers containing PDADMAC on the crystallinity was studied by X‐ray diffraction. These results reflect good effect of grafting on the optical and structural properties of nylon‐6 fibers. The opto‐thermal properties of grafted PAA with different graft yields have been studied. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Comparative investigation on the structural,morphological, optical,and magnetic properties of CoFe2O4 nanoparticles

Herein, we report a sustainable production of magnetic cobalt ferrite nanoparticles by conventional (CHM) and microwave heating (MHM) method. Hibiscus rosa-sinensis extract was used as both reducing and stabilizing agent. Using plant extracts to synthesize nanoparticles has been considered as an eco-friendly method, since it avoids noxious chemicals. The plethora of plant extract mediated nanoparticles were compared by techniques, such as XRD, Rietveld, FT-IR, SEM, EDX, UV-Visible DRS, PL and VSM were carried out to analyze and understand their crystallite size, functional groups, morphology, optical and magnetic properties. The crystalline structure of cobalt ferrite nanoparticles revealed the cubic structure and the microwave heating of nanoparticles showed smaller crystallite size compared to the conventional heating, which was then confirmed by XRD analysis. To analyze the presence of functional groups and the phytochemical involvement of the plant extract was confirmed by FT-IR studies. Spherical morphology with less than 100 nm sized particles was confirmed by SEM and EDX analysis confirm the existence of Co, O, and Fe elements present in the samples. UV-Visible DRS studies were carried out to calculate the band gap of the as-synthesized nanoparticles, estimated from the Kubelka-Munk function, as 2.06, and 1.87 eV for CHM and MHM, respectively. Photoluminescence emission spectrum of the nanoparticles showed two different bands at 494 and 620 nm, which explores the optical properties of the nanoparticles, due to the quantum confinement effect. VSM analysis showed better ferromagnetic behavior, which can be used for magnetic applications.