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Pure and neodymium (Nd) substituted yttrium oxide nanoparticles were synthesized by the co-precipitation technique. The synthesized materials were annealed at 350°C, 500° C, 750° C and 1000° C using a muffle furnace at an open atmosphere. X-ray diffraction patterns, FTIR spectra and XPS spectra were recorded to study the structural variations. The morphology has been studied through high-resolution SEM images. The elemental analysis was carried out using energy-dispersive spectral analysis by X-rays. The particle sizes and crystalline nature of the annealed samples were studied by transmission electron microscopic images and their corresponding SAED patterns. The photoluminescence spectral analysis indicated that the pure, as well as Nd-substituted materials have emissions in the blue and green regions. It is also observed that the substitution of Nd has enhanced the emission in the blue region. Moreover, the photoluminescence of Nd-substituted Yttrium oxide has a significant variation with respect to annealing temperatures. [ABSTRACT FROM AUTHOR]

Co-based compounds such as Co3O4, CoS, and CoSe2 were produced via uncomplicated hydrothermal technique. The cubic, hexagonal, and orthorhombic phases of various products were revealed employing X-ray diffraction spectra. The scanning electron microscope images revealed different nanostructures, such as triangular Co3O4 nanoplates, flower-like CoS nanopetals, and CoSe2 nanocubes, of the synthesized materials. The electrochemical performance of Co3O4, CoS, and CoSe2 was determined using electrochemical application studies. Among these three electrodes, notably CoS, showed 577 F/g capacitance at 10 mV/s and an oxygen evolution reaction (OER) performance of 260 mA/cm2 at 10 mV/s scan rate with very low 194 mV overpotential. From the comparative analysis of different Co-based derivatives, it was found that controlled synthesis of CoS, which results in a unique morphology and good OER performance, could be considered as a potential candidate for device applications. [ABSTRACT FROM AUTHOR]

Pure and cobalt (Co)-doped tin oxide (SnO2) nanoparticles were prepared by using a simple co-precipitation method, and the effect of doping on structural, morphological and optical properties was studied. X-ray diffraction revealed a cassiterite tetragonal SnO2 structure with the space group of P42/mnm and without crystalline phases for the samples-doped with higher concentrations. The average crystalline size was found to be between 26.4 nm and 23.1 nm. Fourier-transform infrared spectra depicted the presence of O-H, C-H and Sn-OH absorption bands. It was observed from ultraviolet-visible spectra that the optical band gap values were decreased from 3.69 eV for pure SnO2 to 3.47 eV for 7% Co-doped SnO2. The photolumenescene emission spectra showed that the defect- and emissions-related peaks and the intensity of the peaks decreased with increasing Co concentrations. The presence of tin, oxygen and Co species were found from energy dispersive x-ray spectra. The photocatalytic activities of pure and Co-doped SnO2 nanoparticles were investigated by studying the photodecomposition of brilliant green dye, an organic pollutant. The 7% Co-doped SnO2 had higher photocatalytic activity compared to the pure SnO2, and a maximum degradation efficiency of 91% has been obtained under visible light irradiation. [ABSTRACT FROM AUTHOR]

Detection of uric acid (UA) is a foremost area of research as abnormal increases in its level can be used to diagnose diseases such as gout, renal disorders, and arthritis. Development of efficient test diagnostics to detect UA in human urine is therefore required. In this study, magnesium oxide was prepared via a hydrothermal route. X-ray diffraction analysis revealed formation of amorphous cubic MgO. The transverse optical phonon mode of cubic MgO was confirmed at the zone center at ~ 479 cm−1. Emission peaks observed at 362 nm, 383 nm, 495 nm, and 521 nm showed the high-quality luminescent behavior of the undoped MgO. Scanning electron microscopy images confirmed formation of MgO microflowers. Cyclic voltammetry results confirmed the excellent electrocatalytic ability of Ni/Co-codoped MgO nanostructures. Chronoamperometry (CA) results confirmed that the synthesized Ni/Co-codoped MgO nanostructure possessed good stability under UA. Such transition-metal element-codoped MgO microflowers with improved performance could be suitable as an excellent tool for clinical diagnostics. [ABSTRACT FROM AUTHOR]

Pristine ZnO and Ag-implanted ZnO hierarchical nanoflowers have been successfully synthesized via facile hydrothermal route for photoelectrochemical (PEC) water-splitting applications. The wurtzite hexagonal structural properties have been confirmed by X-ray diffraction (XRD), Raman, and Fourier transform infrared spectra analyses. As Ag content increases, the intensity of cation-sensitive plane (002) also increases, which has been pronounced by XRD result. The optical properties before and after Ag implantation have been thoroughly studied by photoluminescence and Ultraviolet-Visible diffuse reflectance spectroscopy spectra. The optimum concentration of 10% Ag-implanted ZnO possessed the minimum optical band gap of 3 eV. The visible particle size reduction with the increase of Ag concentration and also urchin like typical microflower morphology of synthesized nanostructures has been revealed by scanning electron microscopic images. The typical PEC behavior with 75.14 µA/cm2 versus RHE has been observed in 10% Ag-implanted ZnO nanoflowers. Increase of Ag concentration enhances the electrocatalytic behavior of the photoanodes, which had been revealed in our study. Photostability over 3 h with 40% of retention has been reported in 10% Ag-implanted ZnO hierarchical nanoflower photoanodes. Hence, the optimum concentration of Ag implantation with ZnO could be adapted as an excellent photoanode for PEC water-splitting applications. [ABSTRACT FROM AUTHOR]

The manuscript presents structural, optical and magnetic properties of CuFeO nanoparticles obtained employing a simple co-precipitation method in aqueous solution. Influence of ferric chloride concentration on the structural, optical and magnetic properties of CuFeO nanoparticles was investigated. XRD results clearly revealed the spinel tetragonal copper ferrite structures. The observed characteristic Raman E, F and A phonon mode of vibrations revealed the tetragonal copper ferrite structures. The observed PL results explored inverse spinel copper ferrite emission peaks in the range of visible region. IR result revealed the metal oxygen intrinsic vibrations of octahedral and tetrahedral sites in the spinel copper ferrite structure. SEM analysis clearly revealed the spherical shape morphology particles sizes are in the nano scale range. VSM studies clearly revealed that copper ferrite exhibit weak ferromagnetic behaviour. It was found that the ferric chloride concentration added to copper chloride precursor in the ratio of 1:1, 1:2 and 1:3 during the synthesis process played a significant role in structural and magnetic properties of the obtained product. [ABSTRACT FROM AUTHOR]

Co doped FeO thin films were deposited by using Iron (II) Sulfate heptahydrate (FeSO·7HO) and cobalt sulfate heptahydrate (CoSO·7HO) as precursors using SILAR method. Structural analysis using XRD reveals a decrease in crystallite size with doping is due to the accommodation of dopant atoms into the host matrix and excess atoms occupy the interstitials. In accordance with this dislocation density is found to be increased with increasing doping concentration. XRD results also reveal that Co is substituted into the Fe lattice, since both Fe and Co have same ionic radii and hence the structural properties of the thin film are intact with minor internal modifications. Raman analysis was used to find the vibrations and the polymorphs of iron oxide and the doping. The morphology of the samples was studied using FESEM. Absorption and transmission spectra of the deposited thin films were analyzed using UV-Vis spectrometer, the absorption value decreases with increase in wavelength whereas, transmission value increases with increase in wavelength. The defects in the deposited films were studied using PL studies. Magnetic properties were analyzed using VSM and it confirms the exchange interactions between the dopant and host atoms. [ABSTRACT FROM AUTHOR]

Magnetite thin films were deposited by varying the temperature of the bath in the SILAR deposition process. Structural, morphological and optical properties of the deposited films were analyzed using X-ray diffraction, Raman spectroscopy, Field emission scanning electron microscopy, UV-Visible spectroscopy. With the increase in bath temperature of the deposition process, crystallite size decreases and dislocation density and microstrain increases. Raman spectra confirm the formation of magnetite phase for all the deposited films. FESEM images reveal the bath temperature's influence on the surface morphology. Considerable variations in the optical properties were observed for the films and were discussed in detail. [ABSTRACT FROM AUTHOR]

Nanocrystalline magnetite thin films were deposited on glass substrates using simplified SILAR method. Variations in structural, optical and magnetic properties were studied with respect to annealing temperature. XRD results reveals the nanocrystalline film formation of cubic structured magnetite (FeO), whose crystallite size increases with annealing. SEM images shows the spherical morphological agglomeration which varies with annealing. Transmission in UV-Vis radiation increases with annealing of films and maximum % transmission was observed for near IR range. VSM result reveals the magnetically soft nature of the deposited films with increasing M, H values on annealing. [ABSTRACT FROM AUTHOR]

In this paper, we report the structural, optical and magnetic properties of nano crystalline samples of Zn(TM)O (TM = Ni, Co and x = 0, 0.05, 0.10 and 0.15) synthesized by co-precipitation method. The synthesized samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), photoluminescence (PL), micro-Raman, and vibrating sample magnetometer (VSM). It is observed from XRD patterns that all the samples reveal polycrystalline hexagonal wurtzite structure without any extra phase and average particle size decreased with increasing transition metal (TM) doping concentration. FTIR spectrum has been used to confirm the functional group of Ni-O and Co-O bond. SEM images demonstrated the grain like morphologies of TM doped ZnO nanoparticles (NPs). PL spectra of all samples exhibited a broad emission in the visible range. The carriers (donors) bounded on the TM sites were observed from the micro Raman spectroscopic studies. TM doped ZnO NPs showed significant changes in the M-H loop where the diamagnetic behavior of ZnO changes to ferromagnetic nature when doping with Ni and Co ions. [ABSTRACT FROM AUTHOR]

Defect pyrochlores of composition KM 0.33 Te 1.67 O 6 (M = Al, Cr and Fe) were prepared by solid state method. Structural, morphological and optical properties of these materials were obtained by XRD, Raman, SEM, particle size analyser, and UV–Visible diffuse reflectance techniques. The lattice parameter “ a ” was deduced for all the materials from Rietveld refinement program, Fullprof.2k by refining d-lines. The photocatalytic activities of these materials were evaluated by photodegradation of methylene blue. The mechanistic degradation pathway of methylene blue (MB) was studied in the presence of KAl 0.33 Te 1.67 O 6 using terepthalic acid. The DC conductivity measurements of all compositions were carried out in the temperature range 373–673 K. The variation of conductivity with temperature is explained. [ABSTRACT FROM AUTHOR]

Pure and ZnCoO (x = 0.05, 0.10 and 0.15) nanoparticles were synthesized by co-precipitation method. Powder X-ray diffraction studies confirmed that pure and Co doped ZnO have a single phase nature with hexagonal wurtzite structure and Co ions were successfully incorporated into the lattice position of Zn ions in ZnO matrix. FTIR and EDS spectra results confirmed the incorporation of the dopants into the ZnO lattice structure. FESEM images showed the flower like morphology in ZnO and flowers are dispersed to grains in Co doped ZnO nanoparticles. The chemical composition of ZnCoO nanoparticles were confirmed by XPS. The XPS results clearly showed the existence of Co as a doping element into the ZnO crystalline lattice. Further, the synthesized Co doped ZnO nanoparticles have been used for electrochemical non-enzymatic glucose biosensing. The lowest detection limit of the proposed sensor was found to be 5 µM. The sensor selectively oxidizes glucose in the presence of other interfering compounds like l-dopa, ascorbic acid, hydrogen peroxide and uric acid. [ABSTRACT FROM AUTHOR]

Cerium oxide (CeO) thin films were prepared by rf magnetron sputtering (PVD) technique onto glass substrates at a pressure of 3 × 10mbar of Ar atmosphere. The thickness of deposited CeO films ranges from 380 to 590 nm. X-ray diffraction studies on the films showed that the films are polycrystalline in nature. The crystallite size (D), dislocation density (δ) and micro-strain (ε) were evaluated from XRD patterns. The obtained micro-strain and dislocation density of the films were found to be ~10 and ~10lines/m respectively, along with a marginal increase in crystallite size from ~6 to ~9 nm. The experimental diffraction values of the films agreed with the standard values. The optical properties of cerium oxide films were studied in the wavelength range 325-900 nm. Optical absorption, extinction coefficients, refractive index and optical conductivity were evaluated from optical measurements. The films are found to be highly transparent in visible region and exhibits low reflectance in the ultraviolet region. The optical band gap of the films was found to decrease from 3.53 to 3.45 eV, with the increase of film thickness. The defects were found to increase with the increase of rf power. Emission bands like UV, weak blue, blue, blue-green and green bands were observed from PL spectra of CeO thin films. Raman active mode (F) of CeO thin films was observed at 466 cm and films deposited at higher rf power show increased line width as well as peak intensity in Raman spectra. Rf power induced formations of flower like morphology were observed in SEM images. The surface roughness of CeO thin films was increased from 2.9 to 7.7 nm with the increase of rf power as ascertained from AFM images and the results are discussed. [ABSTRACT FROM AUTHOR]

Cubic-structured NiO, CoO and spinel-structured NiCoO were synthesized via microwave route. The structural properties of NiO, CoO and NiCoO nanostructures were investigated by X-ray diffraction analysis, and it showed smaller crystallite size for NiO than CoO and NiCoO by using Williamson-Hall method. Flake-like and hexagonal plate-like morphologies were ascertained from HRSEM and TEM analyses. Optical properties of these materials were investigated by photoluminescence study, and it presents the band edge emission for all materials with supplementary emissions in visible region due to the presence of defects such as vacancy and interstitial. Raman and FTIR spectra provide the functional characteristics of NiO, CoO and NiCoO nanostructures. XPS measurement revealed the purity and composition of these nanostructures. Room temperature magnetic measurements were investigated using vibrating sample magnetometer. The low coercivity and remanent magnetization for NiO, CoO and NiCoO nanostructures confirmed that these nanoparticles exhibit a weak ferromagnetic behaviour. [ABSTRACT FROM AUTHOR]

An organic second harmonic generation (SHG) active material, ethylenediaminium di(2-nitrophenolate) (EDA2NP) was synthesized through proton transfer reaction. Good quality single crystals of dimension 6 x 4 x 2mm³ were grown by solvent evaporation method using ethanol as a solvent for the first time in literature. The lattice parameters of the grown crystals were determined by X-ray diffraction studies. Fourier Transform Infra Red (FT-IR) spectrum was recorded to identify the presence of various functional groups and the molecular structure was confirmed by nuclear magnetic resonance (NMR) spectrum. Thermal analyses of the grown crystal were carried out using thermo gravimetric-differential thermal analysis (TG-DTA) and differential scanning calorimetry (DSC) curves. Optical (UV-vis-NIR) analysis shows that the grown crystals were found to be transparent (450-2500nm) in the entire visible region. The existence of second harmonic generation signals was observed by using Nd:YAG laser with fundamental wavelength of 1064nm. [ABSTRACT FROM AUTHOR]

Single source precursor, antimony potassium tartrate, was used for the preparation of SbO, KSbO, KSbSbO, and KSbO. Antimony trioxide (SbO) was prepared by hydrothermal method, while potassium antimony oxides (KSbO, KSbSbO, and KSbO) were obtained from the thermal decomposition of antimony potassium tartrate. All the compounds were characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FT-IR), UV-Vis diffuse reflectance spectra, and scanning electron microscopy (SEM). The decomposition process of antimony potassium tartrate with temperature was given. The product formation at different temperatures of thermal decomposition was monitored by PXRD and FT-IR. The TG profile of antimony potassium tartrate shows mass loss at three regions. The infrared spectra of parent and decomposed products gave characteristic Sb-O bands. The band gap energy of decomposed products was obtained. The SEM diagrams of SbO show different morphologies. Direct solid state preparation of KSbO and KSbSbO under identical experimental conditions was unsuccessful. [ABSTRACT FROM AUTHOR]

Nano sized defect pyrochlores of compositions KCrWO and ACrWO· nHO (A = Sn, Ag, Bi, Sm, Eu, and Gd) have been synthesized by sol-gel and ion exchange methods, respectively. These oxides were characterized by thermogravimetric analysis, powder X-ray diffraction, energy dispersive spectra, transmission electron microscopy, UV-Vis diffuse reflectance spectra, Raman spectra, and Fourier transform infrared spectra. Spontaneous exchange of K with A ion is accompanied by insertion of water also into the lattice. KCrWO and ACrWO· nHO crystallize in cubic lattice and isomorphous with KSbWO. The optical properties of Cr were investigated. Substitution of K by A ion leads to a shift of absorption onset to longer wavelengths marginally. The Raman spectra of all the samples are characteristic of defect pyrochlore system. The photocatalytic degradation of methylene blue aqueous solution was investigated using these oxides. The results obtained were fitted with the Langmuir-Hinshelwood model to study the degradation kinetics. Both Sn and Bi-doped KCrWO exhibit higher photoactivity in the degradation of methylene blue. The structure/composition of the photocatalyst remains the same even after fourth cycle of photodegradation. [ABSTRACT FROM AUTHOR]

Tuning the morphology, size and aspect ratio of free standing ZnO nanostructured arrays by a simple hydrothermal method is reported. Pre-coated ZnO seed layers of two different thicknesses (≈350 nm or 550 nm) were used as substrates to grow ZnO nanostructures for the study. Various parameters such as chemical ambience, pH of the solution, strength of the Zn atoms and thickness of seed bed are varied to analyze their effects on the resultant ZnO nanostructures. Vertically oriented hexagonal nanorods, multi-angular nanorods, hexagonal diskette and popcorn-like nanostructures are obtained by altering the experimental parameters. All the produced nanostructures were analysed by X-ray powder diffraction analysis and found to be grown in the (002) orientation of wurtzite ZnO. The texture co-efficient of ZnO layer was improved by combining a thick seed layer with higher cationic strength. Surface morphological studies reveal various nanostructures such as nanorods, diskettes and popcorn-like structures based on various preparation conditions. The optical property of the closest packed nanorods array was recorded by UV-VIS spectrometry, and the band gap value simulated from the results reflect the near characteristic band gap of ZnO. The surface roughness profile taken from the Atomic Force Microscopy reveals a roughness of less than 320 nm. [ABSTRACT FROM AUTHOR]

• Bi dopant effect on Cu 3 (VO 4) 2 showed higher current density 1.29 mA/cm2. • Long time stability of photoelectrode for 6 h of illumination was reported. • Phase changing mechanism of Bi in copper vanadate were proposed. Producing clean energy by using low cost and efficient photoelectrodes via hydrothermal method was achieved. Bare CuV 2 O 6 monoclinic structure and structure/phase changing mechanism of Bi dopant in CuV 2 O 6 and conversion mechanism of Cu 3 (VO 4) 2 anorthic phase from CuV 2 O 6 monoclinic was revealed by X-ray diffraction (XRD). Band gap variations of two different phases and dopant, morphological effect on band structure of product were examined. Photoelectrochemical performance of fabricated electrodes was analyzed by linear sweep voltammogram (LSV), electrochemical impedance spectra (EIS), and chronoamperometry (CA) studies under illumination. Synergistic effect of nanoflower morphology and Bi dopant effect on Cu 3 (VO 4) 2 phase showed higher current density of 1.29 mA/cm2 in LSV with high electronic conductivity. Long time stability of same photoelectrode for 6 h of illumination was reported. Phase and morphological changing mechanism of Bi dopant in copper vanadate were proposed and proficient electrode was suggested for efficient photoelectrochemical water splitting. [ABSTRACT FROM AUTHOR]

MnMoO4 nanoparticles were synthesized by employing solvothermal method at optimized experimental condition to explore their electrochemical properties. The fundamental characterization studies such as X-ray diffraction, Raman spectroscopy, and Fourier transform infrared spectra confirmed the formation of pure phase of monoclinic crystal structure with C2/m space group. X-ray photoelectron spectroscopy studies revealed that the core-level Mn-2p spectrum peaks observed at 641.2 eV can be attributed to Mn-2p3/2 and that at 654.1 eV can be indexed to the binding energy of Mn-2p5/2. Major infrared peaks observed at 725, 800, 867, and 946 cm−1 could be designated to the characteristics bands of tetrahedral MoO4 groups in MnMoO4 nanoparticles. Raman peaks observed at 351, 823, 886, and 932 cm−1 corresponded to characteristics bands for MnMoO4 nanoparticles. The cyclic voltammetry studies at different scan rates (i.e., 10, 20, 30, 50, 80, and 100 mV s−1) were performed for all three MnMoO4 nanoparticles and displayed similar redox peaks in the positive and negative current regions, reflecting the pseudocapacitive nature. From galvanostatic charge-discharge profiles, it was found that MnMoO4 nanorods (R2) show high- capacitance of 697.4 F g−1 at 0.5 A g−1 current density and 40% increment in specific capacitance than other nanoparticles and can be considered as suitable nanomaterials as electrode for energy storage applications. [ABSTRACT FROM AUTHOR]

Tungsten oxide nanostructures were developed on indium tin oxide coated glass substrates by modified thermal evaporation process without using catalyst and vacuum. Depending on the substrate temperature and vapor concentration, different nanostructures like rod, sheet and pyramid were formed. Morphology, phase structure and crystallinity of the nanostructure films were characterized by Scanning electron microscope (SEM), X-ray diffraction (XRD), Raman spectroscopy and HR-TEM. The samples were investigated under dark current and photocurrent and in H 2 SO 4 aqueous solution as a function of applied potential. The saturated photocurrent density of tungsten oxide was found to be ≈14.4 μA cm −2 . The films were also investigated as resistive gas sensor for ethanol gases (10–50 ppm) at room temperature. The response and recovery time were also determined. [ABSTRACT FROM AUTHOR]

• Orthorhombic SrV 2 O 6 was confirmed employing X-Ray diffraction. • 0.01 M citric acid assisted SrV 2 O 6 explored 29.11 m2/g high surface area. • 0.01 M CA-SrV 2 O 6 exhibited 78 and 337 mV to deliver 10 and 100 mA/cm2. • It displays better catalytic performance with low 83.3 mV/dec Tafel slope. A novel strontium vanadate for electrochemical hydrogen evolution reaction was reported. SrV 2 O 6 orthorhombic phase was confirmed employing X-Ray diffraction with 34, 29 and 34 nm crystallite size of pristine, 0.01 and 0.02 M citric acid assisted SrV 2 O 6. 0.01 M citric acid assisted SrV 2 O 6 high BET surface area was 29.11 m2/g. Electrochemical HER performance revealed that low concentration of citric acid assisted SrV 2 O 6 nanostructure exhibited 78 and 337 mV low overpotential to deliver 10 and 100 mA/cm2 current density. It displays better catalytic performance with low 83.3 mV/dec Tafel slope and small charge transfer resistance of 30.6 Ω. Hence, excellent HER activity may be ascribed due to existence of high surface area, unique one-dimensional morphology and synergetic effect between strontium and vanadium oxides. [ABSTRACT FROM AUTHOR]

Abstract: Nano-sized Cu2+ and Ag+ doped sodium trititanate (Na2Ti3O7) were prepared by a facile acid-free ion-exchange method in an aqueous solution at room temperature. All the samples were characterized by TGA, FESEM, EDS, Powder-XRD, UV–visible DRS and FT-IR spectroscopic methods. Both Cu2+ and Ag+ doped Na2Ti3O7 were crystallized in monoclinic lattice with P2 1 /m space group. The band gap energies of all the samples were deduced from their UV–visible DRS profiles. Visible light-induced photocatalytic oxidation of the methylene blue (MB) dye has been examined in the presence of all the trititanates aqueous dispersion. The Ag+ doped trititanate exhibited remarkable photocatalytic activity in the degradation of methylene blue (MB) dye under visible light irradiation. Photochemical degradation of cyclohexa-1,4-diene and phenol also were examined in presence of these titanates. [Copyright &y& Elsevier]

Abstract: l-arginine phosphate monohydrate (LAP), potassium thiocyanate (KSCN) mixed LAP (LAP:KSCN) and sodium sulfite (Na2SO3) mixed LAP (LAP:Na2SO3) single crystals were grown by slow cooling technique. The effect of microbial contamination and coloration on the growth solutions was studied. The crystalline powders of the grown crystals were examined by X-ray diffraction and the lattice parameters of the crystals were estimated. From the FTIR spectroscopic analysis, various functional group frequencies associated with the crystals were assigned. Vickers microhardness studies were done on {100} faces for pure and additives mixed LAP crystals. From the preliminary surface second harmonic generation (SHG) results, it was found that the SHG intensity at (100) face of LAP:KSCN crystal was much stronger than that of pure LAP. [Copyright &y& Elsevier]

Transparent and conducting cadmium oxide (CdO) thin films were deposited on glass substrates at room temperature using radio frequency (RF) magnetron sputtering method. The carrier concentration and electron mobility are the key factors for the conducting properties of CdO thin films. The grain size, crystallinity, thickness, surface roughness and band gap of CdO thin films play an important role in optical and electrical properties. In this study, dual behaviour of CdO thin films is studied as a function of RF sputtering power. Crystalline quality, micro structure, surface morphology and optical and electrical properties of sputtered CdO thin films were investigated. The structural analysis revealed that the deposited CdO films were polycrystalline in nature with cubic structure ( Fm 3 ¯ m space group). The grain sizes were found to be increased with increase of RF power from 100 to 150 W and then decreased at high power (200 W). The optical studies revealed that all the films exhibited higher transmittance in visible and near infrared region and the optical energy band gap value decreased from 2.62 to 2.46 eV with increase of RF power. Luminescence spectra exhibited two strong emission peaks at 484 and 519 nm. The resistivity of CdO thin films gradually decreased with an increase of sputtering power and reached a minimum value of 3.041 × 10 −4  Ω cm at 200 W. A maximum mobility of 67.01 cm 2 /Vs was found for the sample prepared at the sputtering power of 150 W. [ABSTRACT FROM AUTHOR]

Single phase cadmium stannate thin films were deposited on glass substrates through rf magnetron sputtering by varying rf power and keeping substrates at room temperature. The effect of rf power on physical properties of the films and the correlations were systematically investigated. It has been found from XRD that structural phase transition occurred from amorphous to spinel structure with increase of rf power. AFM images revealed that the deposited films show smooth surface with nano grains. High transmittance was retained by the films in visible region and the band gap was decreased from 3.05 to 2.49 eV for increasing rf power by quantum confinement effect. The Mott-Davis model and drude model were used to evaluate the optical constants and free carrier absorption. The electrical resistivity of the films varied in three orders of magnitude as a function of rf power which could be explained by oxygen vacancies formation. From these results, the films deposited at 150 W has the low resistivity of the order of 10 −3 Ω cm with high optical transparency as 80% which could be the preferred conditions to deposit high quality films for future TCO layers for cadmium based CdTe/CdS solar cell devices. [ABSTRACT FROM AUTHOR]

Ag-doped cobalt oxide (Co 3 O 4 ) nanorods were successfully synthesized using hydrothermal route at 90, 120, 150, and 180 °C. The face-centered cubic structure of Co 3 O 4 was confirmed through X-ray diffraction pattern. A well-defined Raman active mode of vibrations (E g + F 2g + A 1g ) revealed the cubic Co 3 O 4 formation. The morphology of Ag-doped Co 3 O 4 nanorods was revealed from scanning electron microscopy images. High specific capacitance of 584 F/g at scan rate of 5 mV/s was obtained for the product synthesized at 150 °C. The improved oxygen evolution reaction (OER) for the synthesized materials was observed using linear sweep voltammogram, electrochemical impedance spectroscopy, and chronoamperometry. The obtained Ag-Co 3 O 4 nanomaterials have more possibility to be adapted as OER catalyst for water splitting application. [ABSTRACT FROM AUTHOR]

ZnO nanowire arrays (NWAs) were synthesized on ZnO TiO 2 mixed oxide seeded FTO conducting glass plate by two-step sol-gel and hydrothermal method, respectively. X-ray diffraction patterns reveal the presence of mixed and hexagonal phases in seed layer and NWAs, respectively. Scanning electron microscope images showed that the FTO glass plate is uniformly covered with grains and a few nanorods in seed layer and dense NWAs are vertically grown on the seed layer. The hexagonal structure and high crystal quality have been confirmed by micro Raman spectra. Photoluminescence spectra also present that NWAs have high crystal quality and less atomic defects. UV spectra indicate that NWAs are absorbed more dye molecules and it has the band gap equal to bulk material. The efficiency of ZnO TiO 2 mixed oxide seed layer and ZnO NWAs is found to be 0.56 and 0.84% respectively. Electrochemical impedance spectra reveal that NWAs DSSC has high charge transfer recombination resistance than the seed layer DSSC. [ABSTRACT FROM AUTHOR]

CeO 2 and Ni–CeO 2 thin films with cubic fluorite structure were prepared by rf magnetron sputtering. Crystallinity and optical properties of the prepared thin films were studied using X-ray diffraction, UV–vis and Photo Luminescence analysis. Vibrational and magnetic properties of the films were analysed through Raman and VSM analyses. The results from XRD and Raman spectroscopy indicate that doped Ni species were dispersed on the ceria surface. Room temperature magnetic measurements reveal paramagnetic nature of pure CeO 2 thin films and ferromagnetic nature with reasonable saturation magnetisation (4.03×10 −5 emu/cm 3 ) of Ni doped CeO 2 thin films. It is believed that the ferromagnetic contributions exhibited in the M–H loops originate from the absorptive oxygen on the surface rather than the oxygen vacancies in the lattice. [ABSTRACT FROM AUTHOR]

Highly oriented thin films of Al doped ZnO (Al:ZnO) and Cu co-doped Al:ZnO (Cu/Al:ZnO) thin films were successfully deposited by sol–gel spin coating on glass substrates. The deposited films were characterized using X-ray diffraction analysis and found to exhibit hexagonal wurtzite structure with c-axis orientation. SEM images revealed that hexagonal rod shaped morphologies were grown perpendicular to the substrate surface due to repeated deposition process. High transmittance values were observed for pure ZnO compared to Al:ZnO and Cu/Al:ZnO thin films. The band gap widening is caused by the increase of carrier concentration, which is believed to be due to Burstein-Moss effect due to Al and Cu doping. PL spectra of Cu/Al:ZnO thin films indicate that the UV emission peaks slightly shifted towards lower energy side. XPS study was carried out for Zn 0.80 Al 0.10 Cu 0.10 O thin films to analyze the binding energy of Al, Cu, Zn and O. Magnetic measurement studies exhibited ferromagnetic behavior at room temperature, which may be due to the increase in copper concentration in the doped films. The ferromagnetic behavior can be understood from the exchange coupling between localized ‘d’ spin of Cu ion mediated by free delocalized carriers. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two different crystals have grown in a single solution made up of l-histidine and HCl. [•] Structural optical and thermal properties were studied and compared. [•] l-Histidine possesses better properties than l-histidine hydrochloride monohydrate. [Copyright &y& Elsevier]

Abstract: To study the improved characteristics of l-arginine phosphate monohydrate (LAP) crystals, amino acids mixed LAP crystals have been grown by slow cooling method. Amino acids like glycine, l-alanine, and l-valine have been selected for doping. Optical quality bulk crystals have been harvested after a typical growth period of about twenty days. The effect of amino acids in the crystal lattice and molecular vibrational frequencies of various functional groups in the crystals have been studied using X-ray powder diffraction and Fourier Transform infrared (FTIR) analyses respectively. Thermal behavior of the amino acids mixed LAP crystals have been studied from the TG and DTG analyses. High-resolution X-ray diffraction studies have been carried out to find the crystalline nature. Optical transmission studies have been carried out by UV–vis spectrophotometer. The cut off wavelength is below 240nm for the grown crystals. [Copyright &y& Elsevier]