Size-strain Plot Research Articles

Microstructural Analysis and Optical Properties of Lead Zirconate Nanoparticles

Lead zirconate (PZ) nanopowders were synthesized by the treatment of precursors with high-energy ball milling for a relatively short time. The effects of ball milling time and rotational speed on the produced nanomaterial were investigated. The calcination temperature of the ball-milled powder was determined from the thermogravimetric analysis (TGA) and the differential scanning calorimetry (DSC) results. The structural properties of the calcined nanoparticles were studied by Fourier transmission infrared (FT-IR), x-ray diffraction (XRD), and transmission electron microscope (TEM). Well-crystallized PZ nanopowders were obtained after heating at 800°C for 3 h. The diffraction data were refined by the Rietveld method to accurately determine the crystallographic information. Williamson-Hall, Halder-Wagner, and size-strain plot methods were employed to investigate the average crystallite size and lattice microstrain in the prepared samples. The XRD and TEM images confirmed the formation of nanoparticles with an average size in the range of 20–43 nm. The band gap of the nanopowders varied from 3.11 eV to 3.28 eV as established by diffuse reflectance measurement.

Spinel cobalt(II) ferrite-chromites as catalysts for H2O2 decomposition: Synthesis, morphology, cation distribution and antistructure model of active centers formation

Cobalt (II) ferrite-chromites CoCr2-xFexO4 (x = 0.0 ÷ 2.0, step is 0.2) with spinel structure have been synthesized using sol-gel method with citrate metal-polymer precursor. The relations between structural, morphological and catalytic properties of the mixed spinels have been studied. The CoCr2-xFexO4 powders were analyzed using X-ray diffraction analysis, Mössbauer spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive analysis and Brunauer–Emmett–Teller (BET) methods. The average crystallite size was calculated using the Williamson-Hall and size-strain plot methods. Increase of Fe content resulted in increase of the crystallite size from 10 nm (CoCr2O4) to 35 nm (CoFe2O4). Chromium ions were located mainly in octahedral sites, whereas the cobalt and ferric ions were distributed between the octahedral and tetrahedral sites. The lattice parameter was dependent mostly on the octahedral site radius. Superparamagnetic properties of the nanoparticles were described by two-level relaxation model. The samples with a high content of chromium (III) have highly porous structure. Porosity of the samples was decreased with increasing the Fe content. IR spectra contain two peaks corresponding to two characteristic sites in the cubic spinel structure. The mixed ferrite-chromite spinels have catalytic activity in decomposition of hydrogen peroxide. Rate of H2O2 decomposition in the presence of cobalt (II) ferrite-chromite NPs corresponds to the first-order kinetic model. Within 25 min, the decomposition degree is 76.6% with the most active CoFe2O4 sample. Catalytic activity of the samples depends on two factors: the specific surface area and the surface active sites. Antistructure modeling revealed that the tetrahedral Fe(III) sites have electron acceptor properties. The formed Fe(II) ions are active centers in the Fenton-like processes. Probably, the red-ox pairs Co2+/Co3+ in the spinel lattice promote catalytic activity due to acceleration of electron transfer. The spinel cobalt (II) ferrite-chromites are promising catalysts for oxidation of toxic organic impurities in wastewaters with using H2O2.

Investigation on luminescence properties using second-generation (G2) triazolyl chalcone dendrimer as stabilizing agent in Ag@SnO2 core–shell nanoparticles

Ag@SnO2 core–shell nanoparticles were synthesized by a simple, low-cost method using generation 1 (G1) and generation 2 (G2) triazolyl chalcone dendrimer as stabilizing agent. The structural properties were identified using X-ray diffraction (XRD) measurements and transmission electron microscope images. From the XRD values obtained, the average crystallite size and lattice strain of the samples Ag@SnO2-G1 and Ag@SnO2-G2 were calculated using Scherrer formula and the results were compared with size–strain plot. The selected area electron diffraction and XRD analyses exhibited the tetragonal primitive crystal structure with dhkl = 2.3 A, 1.6 A and 1.2 A. The optical properties of the sample were analysed using UV–Visible spectra and photoluminescence (PL) studies. The energy bandgap was calculated using Tau Plot and was found to be direct bandgap of 3.80 eV and 3.85 eV for G1 and G2 samples, respectively. From the PL study, it was evident that the sample Ag@SnO2-G2 emitted photons at 601 nm to the orange region of the visible spectrum confirming a remarkable shift in the wavelength of photonic emission when compared to that of zeroth-generation stabilizer in Ag@SnO2 core–shell nanoparticles. The major shift in the photonic emission exhibits the impact of second-generation dendrimer (G2) on the luminescence property of the synthesized sample and promises favourable results in optoelectronic and photocatalytic applications.

XRD structural studies on cobalt doped zinc oxide nanoparticles synthesized by coprecipitation method: Williamson-Hall and size-strain plot approaches

Cobalt doped Zinc Oxide (Zn1-xCoxO) (x = 0.03) nanoparticles have been synthesized by chemical co-precipitation method at room temperature and characterized by X-ray diffraction (XRD) study. The XRD pattern indicates that Co doped ZnO NPs are with hexagonal wurtzite geometry and diffraction peaks get shifted to higher angles which is the characteristic influence of dopant Co that has an ionic radius smaller than the host cation. The true values of lattice constants have been calculated using Nelson–Riley Function. Crystallite size calculated using Scherrer formula has been compared with that estimated by uniform deformation (UDM), uniform stress deformation (USDM) and uniform deformation energy density (UDEDM) models of Williamson – Hall method, and also by size-strain plot (SSP) method. The lattice strain has also been calculated. The surface morphology and elemental analysis of the product have been characterized by field emission scanning electron microscopy (FESEM) and energy dispersive (EDAX) spectra.

Crystallite size and micro-strain investigations of hydrothermally synthesized β-Ga2O3 by different analytical methods

XRD pattern of [Formula: see text]-Ga2O3 powder, synthesized through template-free two step hydrothermal method at low temperature thoroughly, is investigated by imposing different methods of analysis. Both crystallite sizes and micro-strains of the micro-structures are analyzed and compared. Along with the traditional Scherrer’s formula (S-average, LF and LFTZ), modified Williamson–Hall (W-H) method with UDM, USDM and UDEDM and Size-Strain Plot (SSP) method were used for the investigation. Stress and defect energy densities were calculated from USDM and UDEDM modified W-H plots of the powder sample, respectively. Detailed analysis of the crystallite size and micro-strain from different methods/models was done. Obtained crystallite sizes and micro-strains from different models were compared with the results obtained from TEM analysis. It was found that crystallite sizes obtained from UDM modified W-H analysis and SSP models well coincided with crystallite size observed from TEM micrograph.

Structural parameters of hydrothermally synthesized ZnO nanostructure and their based solar cells

ZnO nanostructure (NS) were prepared via hydrothermal route at various times of heat treatment. The structural properties of ZnO (NS) were reported using X-ray diffraction (XRD) and High-Resolution Transmission Electron Microscopy (HR-TEM). The obtained XRD peaks matched with the standard hexagonal wurtzite crystal structure of ZnO ((ICSD) No. 067454)). Additionally, no noticed peaks corresponded to any phase. The crystal structure, lattice defects and the stress–strain parameters were examined using different models (Size–strain plot method (SPP) Williamson–Hall (W–H) and Halder–Wagner (H–W)), which showed a variation by changing the heating (aging) time (HT). It was found that crystal structure, lattice defects and the stress–strain parameters changed with changing HT. The obtained HR-TEM of the ZnO NS indicated good crystalline structure, spherical and uniform shape. The optical properties of the obtained ZnO NS as a function of HT were described using the spectroscopies: UV–Vis and photoluminescence (PL). The UV–Vis results exhibited a red shift for the absorption band edges, where the estimated optical energy gap (Eg) slightly decreased and shifted to the lower energy region with increasing of HT. The PL emission spectra of the ZnO NS decomposed into two sections ranged from visible to Near-Ultraviolet (NUV). The obtained optical properties are in full agreement with the variation of structural properties obtained using the different XRD models and HR-TEM results. The synthesized particles were used as photoanode in DSSCs sensitized by different organic dyes (Eosin B, Rhodamine B, and Eosin Y). A variation of the overall cell efficiency was observed by changing HT. the sensitizer Eosin Y showed the best efficiency over the other organic dyes with light to electric efficiency of 1%.

Correlating cation distribution with the structural and magnetic properties of Co0.5Zn0.5AlxFe2–xO4 nanoferrites

Unprecedented analysis of the impact of high-level Al3+ substitution on the structural and magnetic properties of low-coercivity Co0.5Zn0.5AlxFe2−xO4 (0.3 ≤ x ≤ 0.8) nanoferrites prepared via autocombustion method is presented. Single-phase cubic structure has been assured for all samples using XRD patterns and FTIR spectra. Due to the notable difference in the ionic radii of Fe3+ and Al3+, structural defects are created for high substitution levels, which is to be balanced by cation redistribution and/or the appearance of Fe2+ and Co3+ cations. Rietveld analysis and size-strain plots were used to explain the non-monotonic change of the lattice parameter, microstrain and crystallite size. For the as-prepared samples, the estimated size ranged from 9 to 19 nm, which was confirmed by HRTEM images. Magnetic properties were deduced from M–H loops traced at room temperature. Saturation magnetization (MS) decreased with increasing Al3+ content while coercivity (Hc) was fluctuating. Based on the experimental data of XRD, FTIR, and VSM, a cation distribution has been proposed and tightly correlated with the structural and magnetic properties. The significant reduction of the lattice parameter and coercivity for the sample with x = 0.8 upon sintering process has been explained in the light of the cation distribution.

X-ray diffraction study of the elastic properties of jagged spherical CdS nanocrystals

Abstract In this work, jagged spherical CdS nanocrystals have been synthesized by chemical method to study their elastic properties. The synthesized CdS nanocrystal has been characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The transmission electron microscope images show that the average size of the nanocrystal is 100 nm approximately. X-ray diffraction (XRD) study confirms that the CdS nanocrystals are in cubic zinc blende structure. The size calculated from the XRD is consistent with the average size obtained from the TEM analysis. The XRD data have been analyzed to study the elastic properties of the jagged spherical CdS nanocrystals, such as intrinsic strain, stress and energy density, using WilliamsonHall plot method. Williamson-Hall method and size-strain plot (SSP) have been used to study the individual effect of crystalline size and lattice strain on the peak broadening of the jagged spherical CdS nanocrystals. Size-strain plot (SSP) and root mean square (RMS) strain further confirm the results obtained from W-H plots.

Intensive comparative study using X-Ray diffraction for investigating microstructural parameters and crystal defects of the novel nanostructural ZnGa2S4 thin films

This paper is devoted to synthesizing good quality polycrystalline ZnGa 2 S 4 thin films of different thicknesses using inexpensive pyrolysis technology for the first time. Then study the crystal structure, crystal defects and the microstructural properties of these films. The novel ternary ZnGa 2 S 4 thin films are investigated by X-ray diffraction, which exhibited that films have polycrystalline tetragonal nature and their space group is I 42 ‾ m ( 121 ) . The compositional elements of films have been investigated using energy-dispersive X-ray spectroscopy and the result is all synthesized films have good stoichiometry . Field-emission-scanning-electron microscope, FE-SEM is used to study the surface morphology of films. An intensive comparative study has been carried out for studying microstructural parameters and crystal imperfections. The corrected integral breadth, β(rad) of observed diffraction lines have been determined by several distribution functions. Major diffraction lines showed that the integral breadth values decrease gradually as thickness increased, while they increase as increasing the diffraction angle of films . Scherrer and Williamson-Hall equations, both the uniform deformation and uniform stress deformation models and the size-strain plot method have been utilized in this study. The results showed that all films have nanosized dimensions and the crystallite size increases with increasing the thickness. The internal stresses, residual microstrian, and lattice microstain are decreasing as the thickness increased. Along with, the crystal lattice distortion, dislocation density and the number of crystallites are also decreasing. Consequently, increasing the thickness of film samples improves their crystallization and reducing their crystalline defects, too. • Novel ternary ZnGa 2 S 4 thin-film samples of different thicknesses have been synthesized. • Several distribution functions were applied to estimate the sample broadening. • A comparative intensive study using X-ray diffractograms was achieved. • Microstructural properties and crystal defects of these samples were estimated and discussed. • Increasing thickness led to improve film crystallinity and reduces crystal defects.

Quantitative analysis of diffraction and infra-red spectra of composite cement/BaSO4/Fe3O4 for determining correlation between attenuation coefficient, structural and optical properties

To better understand the structural and optical properties of composite cement/BaSO4/Fe3O4 for various amount of BaSO4/Fe3O4, the X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy have been used to investigate the correlation between their structural and optical properties. The structural properties including crystallite size, micro strain, stress and energy deformation were analyzed from the quantitative analysis of XRD spectra by using size-strain plot (SSP) methods. The refractive index (n), extinction coefficient (k), dielectric functions (ε), and energy loss function (Im (−1/ε)) were analyzed from the quantitative analysis of FTIR spectra by using kramers-kronig (K–K) relations. The corresponding structures for high amount of BaSO4/Fe3O4 in composite cement/BaSO4/Fe3O4 become less stable which consistent with the distance between the wavenumber of transversal and longitudinal optical phonon vibration mode become shorter. For all composites cement/BaSO4/Fe3O4 in this study, we found that the distance wavenumber (Δ) between longitudinal optical (LO) and transversal optical (TO) phonon vibration decrease with increasing the crystallite size and linear attenuation coefficient. Our results indicated that the FTIR spectra could be useful for determining the optical phonon vibration, dielectric function, and energy loss function of composite cement/BaSO4/Fe3O4.

Influence of PbO phase content on structural and optical properties of PZT nanopowders

Nanocrystalline lead zirconate titanate (PZT) powders were synthesized via a modified Pechini method. The effect of heat treatment temperature on the microstructural properties was studied using X-ray powder diffraction. The explored temperatures were identified from the TGA/DSC measurement and it is found that the crystallization starts from 550 °C. Rietveld refinement was applied to study structural changes and to quantitatively assess the fractional content of lead monoxide, identified in nano-PZT powders. Lebail method was carried out to the XRD pattern to accurately determine the peak broadening and position. Size-Strain Plot and various Williamson-Hall methods were used to calculate the lattice microstrain and crystallite size. The minimum strain was noticed in the pure tetragonal-PZT sample. TEM technique was also employed to study nanopowders and to confirm the formation of small-sized particles. The energy band gap was determined by diffused reflectance measurements and found to range from 3.17 to 3.29 eV.

Bright red luminescence emission of macroporous honeycomb-like Eu3+ ion-doped ZnO nanoparticles developed by gel-combustion technique

The impact of europium (Eu3+) ion doping has been outlined in improving the structure and optical properties of macroporous honeycomb-like zinc oxide (ZnO) nanoparticles, produced by the gel-combustion technique by changing the quantity of dopant. The X-ray diffraction (XRD) research verified that the hexagonal wurtzite structure of ZnO was not disturbed by Eu3+ substitution. Scherrer method, Scherrer plots (SP), Williamson-Hall (W–H) plots and Size-Strain plots (SSP) were used to estimate the crystallite size. Decreased crystallite size in ZnO:Eu3+ was noticed along with lower angle shift of XRD peaks and increased lattice parameters such as unit cell volume that can be described as replacement result of Eu3+ at Zn sites. Fourier transform infrared (FTIR) spectroscopy analysis confirmed the Eu3+ dopant by moving the peak from 474 cm−1 to 525 cm−1. Field-emission scanning electron microscopy (FESEM) pictures verified macroporous honeycomb-like structures. UV–Visible (UV–Vis) absorption spectroscopic studies show that the ability of ZnO:Eu3+ nanoparticles concerning the absorption of visible light increased upon Eu3+ doping with a red shift compared to ZnO nanoparticles. Photoluminescence (PL) emission spectra of Eu3+ doped ZnO nanoparticles exhibited five intense band emissions at 579, 591, 617, 652, and 706 nm ascribed to 5D0 → 7F0, 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3, and 5D0 → 7F4 transitions of Eu3+ ions when excited at 465 nm wavelength, originated from intra-4f transition of Eu3+ ions, respectively. ZnO:Eu3+ nanoparticles intensified with concentration progression and revealed as nanoparticles emitting red under 465 nm excitation.

Electrospinning–calcination combination process on perovskite Ba1-xSrxMnO3 (x=0.03, 0.07, and 0.10) fibers: Characterization study

In the present work, Ba1-xSrxMnO3 (x = 0.03, 0.07, and 0.10) fibers are synthesized by using the electrospinning–calcinations combinations process. The fabricated fibers were characterized by a combination of analytical technique such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy dispersive analysis of X-rays (EDAX), Fourier Transform Infrared (FT-IR), and Diffuse reflectance spectroscopy (DRS). XRD confirms hexagonal structure of Ba1-xSrxMnO3 fibers. A classical size-strain plot (SSP) method has been applied to estimate the microstructure parameters of the produced fibers from the XRD peak broadening analysis. SEM images show the randomly oriented fibers along with diameter growth upon increasing the Sr content. DRS technique was used to estimate the optical band gap of the synthesized samples. The gas sensing study shows the sensing ability of Ba1-xSrxMnO3 fibers, pressed into pellets, toward ethanol vapors.

Investigation on the impact of different stabilizing agents on structural, optical properties of Ag@SnO2 core - shell nanoparticles and its biological applications

Abstract This manuscript details the impact of stabilizing agents on the structural, optical properties of Ag@SnO2 core – shell nanoparticles and its biological applications. Three different stabilizing agent viz. Poly Vinyl Pyrrolidone (PVP), zeroth generation triazolyl glycodendrimer and zeroth generation triazolyl chalcone dendrimer were used as stabilizers in the synthesis of Ag@SnO2 nanoparticles. The results were compared to study their effect on the structural and optical properties of the synthesized samples. The structural parameters of the samples were investigated by XRD analysis, FESEM and HRTEM images. The presence of SnO2 shell on the Ag core was also corroborated by XPS results. The XRD data was used for refining and characterizing the elements present in the sample by Reitveld method. The average crystallite size, dislocation density, lattice parameters (a, c), lattice strain of the samples were calculated using XRD measurements. Williamson – Hall (W-H) method and Size – Strain Plot (SSP) method were used to calculate the lattice strain of the synthesized sample. The concentric rings of the SAED pattern and the lattice fringe images exhibited the interplanar d-spacing values and the results were compared with XRD measurements. The optical properties of the samples were investigated using UV–Vis spectra and the band gap energy were calculated using Tauc plot. The Photoluminescence (PL) studies of the Ag@SnO2 core – shell nanoparticles with the three stabilizing agents are also discussed in this work. The antibacterial and antifungal activities of the chalcone dendrimer stabilized Ag@SnO2 core – shell nanoparticles were tested against the pathogens Bacillus subtilis, Proteus mirabilis, Candida albicans and Aspergillus niger.

Investigation of structural electron density distribution and enhanced electrochemical properties of spinel structured MnCo2O4/polyaniline nanocomposite prepared by facile and economical method

A nanocomposite of AB2O4 structured binary metal oxide and conducting polymer was synthesized by cost effective procedure. The procedure for synthesis of chosen MnCo2O4 was solution combustion method and the composite MnCo2O4/polyaniline was obtained by physical blending. The procedure involved was very simple, speedy and inexpensive. The derived results from Scherrer and size strain plot methods showed good concurrence. The Strain value of the composite from Scherrer was 0.3406 and from SSP was 0.3332. Lattice parameter revealed in Rietveld method also matched well with Scherrer. The observations of functional groups through FT-IR confirmed the purity of the samples and presence of polyaniline and metal oxide. The morphological changes examined through High Resolution Scanning Electron Microscopy, favored enhanced conductivity in the composite showed that the changes occurred have facilitated more conductivity in the MnCo2O4/polyaniline composite. The size of the nanoparticle revealed by High Resolution Transmission Electron Microscopy (HR-TEM) was 8–50 nm, showing good concurrence with the size observed in XRD which was 10–65 nm and shape in SEM. Selected Area Electron Diffraction patterns were also in confirmation of crystallinity of the samples and planes revealed by XRD. The variations in bond length and electron density distribution investigated by MEM technique, a unique report in this work also assured the improved energy storage potential of the nanocomposite material. The electro chemical analyses viz., cyclic voltammetry, chronopotentiometry and Electrochemical Impedance Spectroscopy by a three electrode assemblage with 6 M KOH as electrolyte have supported the above findings by confirming higher specific capacitance and low resistance. In the nanocomposite material synthesized. The maximum specific capacitance of the MnCo2O4/polyaniline nanocomposite was 875 F/g and, the pure MnCo2O4 was 713 F/g at the scan rate 5 mV/S. The ESR value for pure was 4.07 Ω and that of the composite electrode was 2.75 Ω.

Inversion degree, morphology and colorimetric parameters of cobalt aluminate nanopigments depending on reductant type in solution combustion synthesis

Blue-colored ceramic nanopigments with the composition of CoAl2O4 were synthesized by solution combustion method using glycine (CoAl2O4-Gly), poly(vinyl alcohol) (CoAl2O4-PVA) and urea (CoAl2O4-Urea) as reductants and fuels. The morphology and chemical composition of the nanopigments were studied using SEM and EDS, respectively. The composition of the crystalline phase was examined using XRD. The crystallite sizes were calculated using the modified Scherrer method, Williamson-Hall method and size-strain plot method. Particles of the CoAl2O4-PVA sample have smaller crystallite sizes, whereas particles of the CoAl2O4-Urea sample have larger crystallite sizes. Thermal gravimetric analysis showed that thermal decomposition of cobalt(II) and aluminum nitrates is accompanied by the release of gases. As a result of material loosening, finely dispersed powders with high porosity were formed. FTIR-spectra of all the nanopigments contain absorption bands related to stretching vibrations of the Me-О bonds (400-700 cm−1). Stretching and deformation vibrations of water molecules are present as well. Color characteristics of the obtained nanopigments depend on the fuel used for the combustion synthesis. The pigment CoAl2O4-PVA has saturated blue-green color. The obtained spinel-type nanomaterials possess high suspension stability and can be used as pigments in ceramic technology.

Modification of structural and magnetic properties of Co[formula omitted]Ni[formula omitted]Fe2O4 nanoparticles embedded Polyvinylidene Fluoride nanofiber membrane via electrospinning method

Ferrite nanoparticles have garnered significant attention due to their remarkable ferromagnetic properties. However, the functionality of the ferrite nanoparticles can be enhanced with the development of nanofiber membranes. This helps to control the surface, structural and magnetic properties of the composite nanofiber membrane. Herein, we report the fabrication of novel nanofiber membrane containing Co0.5Ni0.5Fe2O4-Polyvinylidene Fluoride (PVDF) via electrospinning method. The Co0.5Ni0.5Fe2O4 nanoparticles were synthesized with the help of sol–gel combustion method. Investigations on the effect of Co0.5Ni0.5Fe2O4 nanoparticles embedded within PVDF polymer nanofiber membrane on structural, morphological and magnetic properties are discussed. XRD line profile analysis revealed cubic spinel structure of the Co0.5Ni0.5Fe2O4 nanoparticles To determine the crystallite size of the samples; Scherrer, Williamson–Hall (W–H), and Size-Strain plot (SSP) were carried out with the help of XRD spectra. The crystallite size of the nanoparticles reduced as they were embedded within PVDF polymer. FTIR studies confirmed that the presence of Co0.5Ni0.5Fe2O4 pristine nanoparticles within the polymeric nanofiber membrane was accountable for the enhanced β-phase bands which makes a significant effect on the ferroelectric properties of the nanofiber membrane. In addition, the VSM technique was used to study the ferromagnetic properties. The enhanced remnant magnetization and saturation magnetization of the nanoparticles was responsible for magnetic nature of the non-magnetic polymer PVDF.

Structural and electrical investigations of pure and rare earth (Er and Pr)-doped NiO nanoparticles

Applying the coprecipitation technique, we synthesized PVA-capped Ni0.98RE0.02O (RE = Er md Pr) nanoparticles. Thermogravimetric analysis (TGA) was performed to study the thermal stability of the prepared samples to choose the calcination temperature accordingly. Thermal stability was attained at ~ 823 K with no further thermal decomposition beyond. The crystallinity and phase formation of the prepared samples were confirmed by powder X-ray diffraction XRD. Studying the effect of RE3+ doping on the structural parameters of NiO nanoparticles was facilitated by X-ray peak profile analysis, based on the Debye Scherer model, Williamson–Hall model and size strain plot. The doped samples exhibited smaller lattice parameter and strain, with the minimum strain along the (200) direction. Also, a smaller crystallite size was found for the doped samples, depending on the dopant’s ionic radius, giving rise to higher dislocation density and specific surface area. Transmission electron microscopy (TEM) proved the nanoscale of the prepared samples, in agreement with the XRD outcomes, and revealed slight agglomeration of homogeneous nanoparticles. DC conductivity indicated the semiconducting behavior of the prepared samples, triggered by Ni2+ vacancies. Hopping mechanism was found to be the conduction process with two activation energies, depending on the temperature range of study. The dielectric behavior was explained by Maxwell–Wagner interfacial polarization, in agreement with Koop’s theory. The correlated barrier hopping mechanism CBH was found to be the conduction mechanism. Moreover, the Nyquist plot was investigated. Doping by rare earth elements resulted in an increase in dielectric constant, AC and DC conductivities.

The effect of precursor concentration and post-deposition annealing on the optical and micro-structural properties of SILAR deposited SnO2 films

Uniform and well-adherent SnO2 thin films, with thickness ranging from 60 nm to 6 μm, were deposited on borosilicate glass substrate by Successive Ionic Layer Adsorption and Reaction (SILAR) technique. A micro-controlled SILAR unit was employed to precisely monitor the deposition conditions. The effect of precursor concentration and post-deposition annealing on the micro-structural and optical properties of SnO2 thin films were studied in detail. The films were found to possess tetragonal rutile structure. The crystallite size of the films increased with solution molarity. Microstructural properties were analyzed using Scherrer, Modified Scherrer, Williamsons-Hall and Size-Strain plot techniques. Different optical properties such as band gap, skin depth, extinction coefficient, Urbach energy etc were determined. The post-deposition annealing at a moderate temperature of 573 K was found to enhance the crystallite size of the films while the density of the defect energy states reduced.

XRD peak profile and optical properties analysis of Ag-doped h-MoO3 nanorods synthesized via hydrothermal method

In the present experiment, we presented the nanocrystalline pure and silver (0.2, 0.4, 0.6, and 0.8 M%)-doped hexagonal molybdenum trioxide rods synthesized by using facile and cost-effective hydrothermal method and analyzed the effects of Ag contents of different microstructural and optical properties. X-ray diffraction (XRD) patterns confirmed the hexagonal crystal structure of the nanorods, supported by FTIR spectra. The Debye–Scherrer formula, Williamson–Hall (W–H), Halder–Wagner (H–W), and size–strain plot (SSP) techniques were applied to investigate different crystallographic characteristics such as crystallite size and lattice strain of h-MoO3 nanorods by evaluating the broadening of XRD peaks. The different relevant structural parameters of the resultant h-MoO3 nanorods connected to XRD analysis such as dislocation density, lattice parameters, unit cell volume, and stacking fault have also been evaluated. The formation of nanorod shape and the presence of Ag contents were confirmed by field emission scanning electron microscope and energy-dispersive spectroscopy, respectively. The optical bandgap was estimated via both Kubelka–Munk (K–M) and Tauc’s rules. The estimated values of the bandgap were found to be in the range of 2.83–3.04 eV. The optical bandgap increased with the increased of Ag contents up to 0.4 M% and afterword decreased up to 0.8 M%. The similar variation trend of optical bandgap was observed for both methods.