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Towards solving the poor electrochemical performance of LiCoPO 4 as a cathode in Lithium-ion batteries, here we propose a novel durable one-pot technique. Mil-88a metal-organic framework (MOF) nanoparticles have been incorporated through LiCoPO 4 synthesis to form a metal-carbon layer after calcination. The structure of our novel cathode has been investigated using XRD, XRF, and TEM. The TEM images showed that the increase in the concentration of Mil-88a to 3% and annealed under air led to forming of a homogeneously distributed shell layer from porous carbon and doped with iron oxide nanoparticles (10–40 nm). The X-ray photoelectron spectra of LiCoPO4@Mil-88a verifies the presence of a Fe-rich surface layer on the nanoparticle surface of LiCoPO 4. The electrochemical studies assured that the 1st cycle yielded a discharge-specific capacity of 138 mAhg−1. The Mil-88a MOF is a basis for metal atoms and carbon, increasing the bulk conductivity. [ABSTRACT FROM AUTHOR]

Highlights • Rose Bengal thin films were deposited on glass substrates with different thicknesses. • Refractive and extinction indices values are calculated by Kramers-Kronig calculations. • Third-order nonlinear optical susceptibility and refractive index values were estimated. • Optical limiting is found to be enhanced by increasing the film thickness. • Rose Bengal is a promising candidate for wide-scale optoelectronic applications and laser power attenuation. Abstract Highly stable Rose Bengal (RsB) organic semiconductor thin films were deposited on glass substrates with different thicknesses ranging from 95 to 325 nm. Optical transmission, reflection, and absorption studies were employed to analyze various optical constants. Refractive index and extinction coefficient values were attained using Kramers-Kronig calculations from the reflectance data. Dielectric constant, loss and dissipation factor were studied. Third-order nonlinear optical susceptibility and refractive index values were estimated using linear refractive index and absorption coefficient data for RsB films and studied their properties in nonlinear media. Optical limiting characteristics are found to be enhanced by increasing the thicknesses of films. The studied films can be used to limit the laser power of wavelengths 632 nm and 532 nm as an optical limiting material. The present work suggests that film of RsB is a promising candidate for wide-scale optoelectronic applications including IR pass filter, laser power attenuation, and selective CUT-OFF laser filters in the wavelength range 490–595 nm. [ABSTRACT FROM AUTHOR]

Zinc telluride (ZnTe) and zinc sulfide (ZnS) thin films were deposited onto glass substrates by the thermal evaporation technique. Their structural characteristics were studied by X-ray diffraction (XRD). XRD showed that both ZnTe and ZnS films are polycrystalline with a zinc blende (cubic) structure. The optical constants ( n , k ), and film thickness ( d ) of ZnTe and ZnS thin films were obtained using two methods, first was based on transmission ( T ) curve obtained by spectrophotometer (SM), using envelope method suggested by Swanepoel and the second was dependent on the ellipsometric parameters ( ψ and Δ) obtained by spectroscopic ellipsometry (SE), using three layer model systems. Both the film thickness and refractive index obtained through these two methods are comparable. The optical band gap was calculated in terms of SE in strong absorption region. The possible optical transition in these films is found to be allowed direct transitions. The increase of E g o p t for both ZnTe and ZnS thin films may be the contributing factor in the increase of crystallites size and decrease in lattice strain. [ABSTRACT FROM AUTHOR]

The PtCl 4 @PVA composites films were prepared by casting an aqueous solutions technique. Based on the effect of PtCl 4 concentrations, the PVA structure was modified from semi-crystal to amorphous material. Corresponding to FTIR and XRD, PtCl 4 is interlinked with a hydroxyl group in the matrix. Both refractive index and extinction coefficient were calculated in the UV–Vis region. The energy gaps of PtCl4@PVA composites films were shifted from 2.58 to 2.43 eV with increasing the PtCl 4 concentrations. Also, the real and imaginary dielectric constants were studied. Furthermore, the volume energy loss function and the surface energy loss function were calculated. Two types of lasers with different input power, as optical limiters, are used to examine the response of PtCl 4 @PVA films with different PtCl 4 concentrations. The present results show that the PtCl 4 @PVA films rely on laser power to attenuate green lasers and He–Ne lasers. The outcome of PtCl 4 @PVA films can be extended to optical applications such as laser filters CUT-OFF. • PtCl4@PVA composites films with various concentrations of PtCl4 were achieved. • The increase in PtCl4 doping improves the optical properties of PtCl4@PVA films. • PtCl4@PVA film is considered an excellent optical material and optical limiter. [ABSTRACT FROM AUTHOR]

In the recent article [Optical materials 95(2019)109219], The authors inform that all the calculations are correct. The equation describes that the extinction coefficient has typewriting mistakes. The authors declare that all the calculations and their related optical parameters based on the extinction coefficient, such as dielectric constant, dielectric loss, optical conductivity, and electrical conductivity, are correct. [ABSTRACT FROM AUTHOR]

In this work, the high quality of CdO film with a different percentage of Ga doping prepared onto optically flat glass substrates using a sol-gel spin coating progression for enhancement of its structural characteristics for various applications. X-ray diffraction results confirm that the prepared films of CdO are amorphous due to the long-range array of deposited crystals. The images of the atomic force microscopy indicated that the surface morphology of the pure and Ga-doped CdO films has high roughness values of 60–80 nm and average particle size 85–100 nm. The optical constants were calculated using the Kramer-Kronig approach. The calculated optical transmission specifies a high transmission exceeding from 77% to 85% through the non-absorbing region depending on the doping concentrations. The results confirm that the measured optical band gap is strongly influenced by doping concentrations of Ga and decreases from 2.35 to 1.72 eV. The calculated optical dispersion and non-linear optical parameters were found to be strongly affected by doping. The terahertz cut-off frequency was set for the pure and Ga-doped CdO films indicating the applicability of the prepared films as terahertz filters. Image 1 • A high-quality thin film of Ga-doped CdO was obtained by a sol-gel spin coating. • The optical band gap is strongly influenced by doping concentrations. • The energy gap is consistent with the oscillator energy, confirming Eo/Eg ≈ 1. • The nonlinear properties support the photodiode-based devices. [ABSTRACT FROM AUTHOR]

Zeolitic imidazolate frameworks (ZIF-8) thin films were fabricated via layer by a layer deposition method. The investigation of X-ray diffraction (XRD) of the ZIF-8 powder form was seen to be polycrystalline with a single cubic-phase structure. The lattice parameters and Miller index were calculated using Rietveld refinement by Fullprof software. XRD of ZIF-8 film demonstrates an amorphous structure. The morphology of the ZIF-8 films has therefore been studied with the scanning laser microscope method and found that the homogeneity and surface enhance with increasing the film thickness. On the other hand, it is found that ZIF-8 films have a direct electronic transition with two energy bandgaps (3.62 and 4.58 eV) and their values independent of the thickness of the films. The optical constants were calculated, and the refractive index esteems increment with expanding of the film thickness. This outcome might be credited to the interlude of the film in the preliminary phase of the deposition. The nonlinear optical constants for ZIF-8 film were calculated, and the third-order optical nonlinearity was expanded with expanding the film thickness. • Fabricate ZiF-8 thin film via Layer by layer deposition method. • Study the optical properties of ZiF-8 thin film. • Study the structural properties of ZiF-8 thin film. [ABSTRACT FROM AUTHOR]

Rhodamine B (RhB) films prepared via spin coater on polyacetate flexible substrates. The X-ray diffraction spectroscopy has been done for RhB/polyacetate flexible substrate and displays an amorphous structure of RhB films in the various thicknesses in the range of 74–303 nm. K-K relations used for determining the refractive index and exhibits a normal dispersion at λ > 600 nm and an anomalous dispersion at λ < 600 nm. The electronic transitions reveal two bands of absorbance Q band which due to the first π→π* transitions and Soret band due to the second π → π * transitions. Also, other linear optical constant such as absorption coefficient, band energy gap, dielectric constants, and optical conductivity were discussed. On the other hand, the first (χ (1) ) and third (χ (3) ) orders of nonlinear optical susceptibilities as well as a nonlinear refractive index (n 2) were calculated and discussed. The electrical and optical conductivities demonstrated the high absorption of RhB/flexible substrates inferring the chance of utilizing these films as optoelectronic gadgets. • Flexible optoelectronic materials have an increasing interest in the advancement of solar energy and biomedicine. • Investigated the optical spectroscopy by Kramers-Kronig (K‑K) method For Rhodamine B (RhB) films. • Calculated the nonlinear optical constants (χ(1)), (χ(3)) and nonlinear refractive index (n 2). • Calculated the electrical and optical conductivities. [ABSTRACT FROM AUTHOR]

Abstract In this work, nanostructured methyl violet-10B (MV-10B) thin films of various thicknesses were coated on glass substrates by a low-cost spin coating method at different rpm. The structural analysis of nanostructured MV-10B thin films was carried out by X-ray diffraction and atomic force microscope. Optical measurements were carried out, and the direct band gap of MV-10B films was estimated. The study showed that the prepared MV-10B thin films act in the same manner as that of conventional direct bandgap semiconductors. From optical studies, the sample exhibited bandpass filter characteristics in IR range from 700 nm to 900 nm and in the visible range centered around 408 nm. Also, the sample absorbs or attenuates the range of wavelengths in the visible spectrum between 470 and 650 nm creating a good absorption band valley making a CUT-OFF laser filter. Optical constants such as refractive index (n) and extinction coefficient (k) were computed using Kramers–Kronig relations. The real and imaginary components of dielectric constant were calculated on the basis of polarization of light when it is impinging on semiconductors. Nonlinear index of refraction and susceptibilities were estimated by linear refractive index dispersion principles. Optical limiting studies showed that the MV-10B thin films are very good optical limiters even at low thickness. The MV-10B showed a laser attenuation behavior for He-Ne and green lasers. The obtained results suggest that the newly designed thin films are the promising candidate in different applications. Highlights • Nanostructured methyl violet-10B (MV-10B) thin films of various thicknesses were coated on glass substrates. • Kramers–Kronig relations were used to calculating the linear and nonlinear parameters of MV-10B thin films. • MV-10B thin films exhibited bandpass filter characteristics in IR range from 700 nm to 900 nm. • MV-10B thin films attenuate the He-Ne laser beam. • MV-10B can be used as CUT-OFF laser filter and laser power attenuations. [ABSTRACT FROM AUTHOR]

In this work, the influence of starch on the structure, and consequently, the properties of manganese oxide have been investigated at room temperature. Different weights of starch have been added to manganese nitrate during a solid-state combustion process. All the samples have been annealed at 600 °C for 2 h. The XRD (X-ray diffraction) and FT (Fourier transform)-Raman spectroscopy have shown the formation of α -Mn 2 O 3 cubic structure for weight ratio equal to or less than (1/5) of starch/ Mn(NO 3) 2 , while above this amount the phase changed to tetragonal phase Mn 3 O 4. The crystallite size calculated via the Scherer equation is ranged from 21.3 nm to 23.8 nm. The strain and the dislocation density have values in the order of 10−3. SEM (Scanning Electron Microscope) indicates a discrepancy in the size and the form of the particles due to the effect of starch weights. The sizes of spherical nanoparticles vary in the range of 780 nm - 30 nm. The energy gap estimated from the theory of Kubelka-Munk is reduced from 3.45 eV to 1.75 eV due to the effect of 0 and 0.5/5 ratio of starch/ Mn(NO 3) 2 and increased again to 2.63 eV for Mn 3 O 4. Also, the dielectric permittivity has been influenced by starch weight. The electrical conductivity depends on the frequency and complies with the universal power law of Jonscher. Mn 3 O 4 nanoparticles have been synthesized at low temperatures with a high percentage of low-cost starch with improved characteristics. Therefore, it is a promising material for the production of lithium manganese oxide to be employed in batteries of lithium. [ABSTRACT FROM AUTHOR]

Corrigendum to "Kramers-Kronig calculations for linear and nonlinear optics of nanostructured methyl violet (CI-42535): New trend in laser power attenuation using dyes" [Phys. Unfortunately, the original version of this article has been published with typewriting mistake in Equation (3) for the extinction coefficient [[1]]. However, our calculations and plots in the text are correct based on the modified equation (1): (1)k( )=2R( )sin ( )1+R( )-2R( )cos ( ), Conflict of interest form There is no any conflict of interest. [Extracted from the article]

In the present investigation, a low-cost and high-operational sol-gel spin coating technique for preparing undoped and various Europium (Er)-doped CdO films of molar percentages of 1%, 5%, 10%, and 15% were considered. Using X-ray diffraction, the polycrystalline nature reveals two preferred orientations of (111) and (200). The mean crystallite size was evaluated and increased from 20.95 to 49.37 nm using the well-known Scherer's formula by increasing the Eu- dopant content. The atomic force microscopy images indicate a homogeneity of a granular distribution deteriorated with Eu-content. The root means square roughness value was evaluated and increased from 4.1 nm to 284 nm with Eu-doping. High transmission of approximately 80% in the visible region spectrum was recorded. The optical band gaps are increased from 2.2 to 2.46 eV from the undoped and various Eu-content %. A relationship between the Eu- content % for CdO films and the optical parameters was discussed to support the availability of the device for optoelectronic applications. [Display omitted] • Films of Eu-doped CdO were produced through a sol-gel spin coating technique. • The effect of Eu-doping on the enhancement of CdO properties was investigated. • The optical constants were computed by the Kramer-Kronig method. • The energy band gap is direct allowed and influenced by Eu- doping. • The results confirm the capability of Eu-CdO for optoelectronic devices. [ABSTRACT FROM AUTHOR]

Modern implants are often based on silicon-doped hydroxyapatite for enhanced biological activity. Such materials still have drawbacks, such as high probability of bacterial infections on their surface during surgery. In this work, we obtained germanium-substituted calcium phosphates, which are isostructural to silicon-substituted hydroxyapatite and whitlockite. Additionally, they potentially possess antibacterial properties. We obtained Ge-substituted phosphate composition Ca 5 GeP 2 O 12 by solid-state, sol-gel, and combustion synthesis. The samples were analyzed using powder X-ray diffraction. Solid-phase synthesis leads to the formation of whitlockite, whereas synthesis in solution leads to the formation of hydroxyapatite. The calculation of the grain size distribution shows that the smallest particles are formed when combustion synthesis is used, and the largest particles are obtained during solid-phase synthesis. This is correlated with the expected influence of stirring and temperature factors on the reaction path. [Display omitted] • Low-temperature syntheses in solutions are an effective way to obtain metastable Ge-substituted hydroxyapatite. • The combustion method produces the smallest particles. • Ge-substituted hydroxyapatite has potential antibacterial properties. [ABSTRACT FROM AUTHOR]

This paper presents the results of a comparative geometric-topological calculation of possible conduction pathways for the Li ​+ ​cation in LiRW 2 O 8 , where R is a cation M3+. Topological analysis based on Voronoi tessellation was performed using the ToposPro software package. We used two critical sets of parameters to construct conductivity channels. As a result, new sets of complex tungstates with lithium were obtained and analyzed. The influence of the structure and size of a triply charged cation on the possibility of fast migration of a lithium cation is discussed. In conclusion, we offer a list of new promising conductors with the formula LiRW 2 O 8. [Display omitted] • The refined topological parameters are required for the prediction of conductivity pathways for lithium-ion in oxides. • New list of tungstates with the formula LiRW 2 O 8 and suitable for fast Li-ion migration are presented. • Substances with the structure of LiYbW 2 O 8 with the space group P2/c are highly promising materials for lithium-ion conductivity. [ABSTRACT FROM AUTHOR]

Structural and optical properties as a function of film thickness have been studied for the thermally evaporated cadmium iodide (CdI 2 ) films. According to XRD structure, the thickness of investigated films extends from 272 to 696 nm, showing hexagonal structure and good c -axis alignment normal to glass substrate plane. Both of crystallite size and lattice strain have been determined in terms of Voight method of the main peak. The optical constants, refractive index ( n ), and extinction coefficient ( k ) have been determined using envelope method. The optical absorption data indicates an allowed direct inter – band transition near the absorption edge with an optical energy gap that decreases continuously from 3.572 to 3.767 eV. Both of optical constants and energy gap show thickness dependence that can be explained in terms of structure parameters, crystallite size, and lattice strain. [ABSTRACT FROM AUTHOR]

The current study proposed outstanding thin films of NaIO 3 doped PVA with higher linear and nonlinear optical parameters using a practical, effective, simple, and low-cost approach. Polymeric thin films based on the combination of the polyvinyl alcohol (PVA), used as a matrix, with sodium iodate (NaIO 3) nanoparticles, considered a filler, were synthesized using a solution casting approach. The structural morphology of pure PVA and NaIO 3 doped PVA nanostructured films was investigated though X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) images. The obtained XRD results concluded an increase in the crystallinity of the host PVA polymer matrix as the weight concentrations of the NaIO 3 dopants increase. SEM images illustrated the external structure morphology of the prepared films, where the cluster agglomeration shows a size increased as increasing the weight concentration of NaIO 3 in the PVA matrix. UV-Vis-NIR spectroscopy was used in this study to study the optical enhancement of the NaIO 3 /PVA nanocomposites as a function of the weight concentration of sodium iodate (NaIO 3) nanoparticles. In this proposed study, it was critical to consider some of the NaIO 3 /PVA optical parameters, including transmittance, absorbance, absorption and extinction coefficients, energy bandgaps, refractive index, optical and electrical conductivities, nonlinear parameters, linear and third nonlinear susceptibilities, and nonlinear refraction coefficient, as well as optical limiting effects. It was observed that with the increase in the NaIO 3 weigh concentrations, the values of the direct and indirect energy bandgaps for NaIO 3 /PVA thin films decrease, compared to the host PVA matrix. The proposed NaIO 3 doped PVA nanocomposites are outstanding promising candidates to pave the way in various optoelectronic devices, taking advantage of the amazing linear optical parameters, huge nonlinear optical properties, low optical energy bandgaps, and large optical limiting. [ABSTRACT FROM AUTHOR]

• Sol-gel spin coating technique is used to prepare pure and Ga-ZnO samples. • First time Kramers-Kronig equations are used to calculate linear and related nonlinear optical parameters. • Ga showed considerable effect on various physical parameters. • High values of χ(1), χ(3) and n(2) were observed for Ga doped ZnO samples. • All the linear and nonlinear parameters quite high compare to previous reports. Pure zinc oxide and gallium-doped ZnO films have been deposited on a glass substrate using a sol-gel assisted spin coating technique. The prepared films were characterized by structural, morphological, optical, and the effect of doping is studied. XRD analyses of the films confirm amorphous nature. Raman studies give support to XRD and confirm secondary phases are absent in the film. The AFM images give the grain size, which decreases with an increase in doping concentration from 116 nm to 81 nm. Roughness, Skewness, and Kurtosis factor are varying from 45.694 nm to 29.153 nm 1.085 to 0.453, 3.583 to 2.605, respectively. Kramers-Kronig equations are the most accurate methodology for optical thin-film technology for the calculations of optical linearity and nonlinearity parameters. The bandgap values are decreasing with increasing thickness from 2.97 to 2.79, respectively. The doped films are more transparent compared to the pure ZnO films. The enhancement in the linear optical properties such as refractive index, absorption index, and dielectric constant are also observed with an increase in the doping concentration. The nonlinear optical properties such as χ(1), χ (3) and n(2) are varying in the range of 0.288 esu to 0.252 esu, 1.1 × 10−12 esu to 7 × 10−13 esu, 1.92 × 10−11 esu to 1.30 × 10−11 esu, respectively. The enhancement in optical properties with increasing the doping concentration suggests the present films are useful for various optical device applications. [ABSTRACT FROM AUTHOR]

• Transparent and conducting Indium (In) doped CdO films deposited sol-gel assisted spin coating technique. • The optical constants were calculated based on Kramers-Kroning relations. • The optical band gap value decreased with doping and is in the range of 2.73 to 2.31 eV. • The linear refractive index value increased with doping concentration, and it was in the range of 2.16 to 2.62. • The present samples are suitable for optoelectronic devices. The different ratios of Indium-doped cadmium oxide thin films were deposited on a glass substrate by a sol-gel assisted spin coating technique. The structure of the films was analyzed using XRD and depicts the amorphous nature of the doped films. All the films are highly transparent, and the value of transparency is around 80 % in the visible region. The optical constants were calculated based on Kramers-Kroning relations. The optical band gap value decreased with doping and is in the range of 2.73 to 2.31 eV. The enhancement in the linear optical properties such as refractive index, absorption index, and dielectric constant was also observed with an increase in the doping concentration. The linear refractive index value increased with doping concentration, and it was in the range of 2.16 to 2.62 indicates that the present sample is useful optical window applications. The nonlinear optical properties such as χ(1), χ (3), and n(2) are varying in the range of 0.005 to 0.468, 3.283 × 10−142 to 7.746 × 10−12 esu, and 7.986 × 10−13 to 1.119 × 10−10 esu, respectively. The enhancement in the optical properties with increasing doping concentration suggests the present films are useful for various optical device applications. The maximum dielectric constants are varying from 4.54 to 6.42, which indicates that the present samples are suitable for optoelectronic devices. Furthermore, nonlinear optical properties were analyzed and reported. [ABSTRACT FROM AUTHOR]

We have developed and tested cell for laboratory operando diagnostics of Li-ion cathode materials. Local atomic and electronic structure of LiFe 1-x Mn x PO 4 olivine cathode was studied by means of Fe and Mn K-edges XAS and Mössbauer spectroscopy. Analysis of XAS data allows us to follow the structural and oxidation state changes occurring during the cell cycling. Together with operando Mössbauer spectroscopy sensitive to the fine Fe ions local coordination distortions escaping from laboratory XANES, we are able to prove the homogeneity of Fe and Mn ions distribution. • Developed the cell for operando XAS and Mössbauer measurements with laboratory equipment. • Separated redox processes for Fe and Mn ions revealed in LeFe 0.5 Mn 0.5 PO 4 cathode. • Oxidation state and local structure changes for d-metal ions during (de)lithiation described. • Homogeneous distribution of Fe and Mn ions in LeFe 0.5 Mn 0.5 PO 4 was confirmed. [ABSTRACT FROM AUTHOR]