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A cost effective and environmental friendly sol-gel autocombustion technique has been used to synthesize spinel ferrite nanoparticles of NixZn1-xFe2O4 (x = 0.0, 0.5 and 1.0). They were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX). While their magnetic properties have been measured at room temperature using a Magnetic Properties Measurement System (MPMS) quantum design magnetometer, the LCR meter (PSM 1735, NumetriQ 4th Ltd U.K.) has been used to study their dielectric properties with variable frequency in the range, 1 Hz-5 MHz. The XRD analysis suggests the presence of cubic spinel structure of ferrites with an average crystallite size of 45-79 nm. The dielectric constant and loss tangent of the samples show a normal dielectric behavior. The variation of dielectric behavior with the frequency is due to the Maxwell-Wagner type interfacial polarization and hopping of electrons between the Fe2+ and Fe3+ ions. The magnetic studies reveal that addition of Zn2+ drastically affects the magnetic properties. [ABSTRACT FROM AUTHOR]

Abstract Al x Cu 0.5 FeNiTi high entropy alloy coating is synthesized by premixed high purity Cu, Fe, Ni and Ti powders on AA1050 aluminium substrate by laser surface alloying, with the aim to improve microhardness and erosion rate. Phase constituents, microstructure and microhardness were investigated using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Vickers Microhardness tester, respectively. The erosion behavior of Al x Cu 0.5 FeNiTi coating is checked using an air jet erosion setup. SEM images show presence of three regions. Percentage compositions of these regions are evaluated using Energy Dispersive Spectroscopy. XRD analysis of Al x Cu 0.5 FeNiTi coating confirmed that these regions are a mixture of disordered BCC and two FCC solid solution phases. The microhardness of the Al x Cu 0.5 FeNiTi HEA is 18 times that of the AA1050 aluminium substrate. Results show that Al x Cu 0.5 FeNiTi HEA coating has improved erosion resistance. Highlights • High entropy alloys possess desirable properties for applications in advanced industries. • Al x Cu 0.5 FeNiTi is alloyed on aluminium AA1050 substrate using fiber laser. • Alloyed bead metallurgical and mechanical characteristics have been analyzed. • Formation of three phase system is confirmed by XRD analysis. • An improvement in microhardness and erosion resistance is achieved. [ABSTRACT FROM AUTHOR]

In the present study attempt was made to synthesize iron nanoparticles in the presence of alumina (Al-nZVI) by sodium borohydride reduction process. The composite adsorbent has been characterized using various analytical techniques such as scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and transmission electron microscopy which showed that iron nanoparticles were partially dispersed on alumina surface, with their diameter being in the range 40-100 nm. The batch adsorption experiments were carried out to study the effect of different parameters. The maximum removal of fluoride was obtained at optimal condition of pH 5.0 and dose = 1.8 g/L and was observed to be 94% with contact time of 60 min at 40 °C and initial concentration of 2 mg/L. The adsorption data fitted that pseudo second order kinetics and followed Langmuir isotherm model with maximum adsorption capacity of 10.06 mg/g. Thermodynamic study revealed exothermic nature of adsorption. [ABSTRACT FROM AUTHOR]

Elliptic-type integral plays a major role in the study of different problems of physics and technology including fracture mechanics. Many papers have been written for various families of elliptic-type integrals. Due to their applications here, we are presenting an organized study of certain generalized family of incomplete elliptic integral. The obtained results are basic in nature have various generalizations. While using the fractional integral operator of Riemann-Liouville type, we found several obvious hyper geometric representations. Which are further used to originate many definite integrals relating to their modules and amplitude of elliptic type generalized incomplete integrals. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Electrospinning fabrication of TiO 2 nanofibers via process parameters are presented. • XRD study showed the presence of mixed anatase and rutile phases. • TG/DTA investigation performed to study the characteristic peaks of TiO 2 /PVP mat. • FTIR investigation endorsed the characteristic peak of Ti O Ti bond. • The optimal process parameters led to preparation of thin TiO 2 nanofibers. Abstract This paper reports the electrospinning fabrication and characterization of TiO 2 nanofibers. Various electrospinning process parameters such as applied voltage, distance tip-collector, solution flow rate and polymer (PVP) concentration are studied. The prepared nanofibers were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), thermogravimetric-differential thermal analysis (TG-DTA) and Fourier transform infrared spectroscopy (FTIR). XRD pattern of TiO 2 nanofibers evidenced the presence of mixed phases of anatase and rutile. TG/DTA investigation showed the characteristic peaks corresponding to the heating behavior of TiO 2 -PVP mat. FTIR investigation endorsed a vibration peak at 660 cm−1 associated with the characteristic Ti O Ti bond. With the optimized process parameters, TiO 2 nanofibers diameter was found to be reduced to 74 nm as compared to the first sample prepared with the diameter of 343 nm. Furthermore, these nanofibers were employed as the photoanode material for the preparation of dye-sensitized solar cell (DSSC) and photovoltaic study is evaluated. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Calotropis procera assisted green route followed for nanoparticle formation. • JCPDS No. 65-3103 confirms Co 3 O 4 nanostructure. • TEM analysis show spherical nanoparticles of average particle size 9.97 nm. • Non-toxic behaviour towards environment. Abstract A novel green synthesis of cobalt oxide (Co 3 O 4) nanoparticles using latex of Calotropis procera via simple precipitation method at room temperature was investigated. An extensive characterization of the product was carried out using X-ray diffractometry (XRD), Differential scanning calorimetry (DSC), Transmission electron microscopy (TEM), Energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and UV–Visible spectroscopy. The results of the characterization confirmed that the synthesized nanomaterial is highly dispersed. TEM analysis revealed that the nano particles are having an average size around 10 nm. The eco-toxic investigation suggested that the particles are non-toxic and safe towards the environment. This green strategy proves to be an effective, fast, simple and cost-effective approach for the synthesis of Co 3 O 4 nanoparticles for various applications. [ABSTRACT FROM AUTHOR]

A novel Mn(III) complex with γ-diketone having general formula [Mn(hdo)3], where hdo = hexane-2,5-dione ligand, has been synthesized and characterized using UV-vis, FT-IR, ESI-mass and EPR spectra, elemental analysis, powder X-ray diffraction, SEM, and magnetic susceptibility measurements. The X-ray diffraction studies reveal that it has monoclinic lattice system with C2/C space group and the unit cell dimensions are a = 9.92245 Å, b = 10.50696 Å, and c = 9.80835 Å. The particle size of this complex has been found to be 32.1 nm. The complex was evaluated for its antifungal activity against Aspergillus flavus, Aspergillus niger, and Aspergillus terreus fungal species. The results indicate that the minimum inhibitory concentration of the synthesized complex was 8 ppm for A. niger while for A. flavus and A. terreus it was 6 ppm. β-Diketone Mn(III) complexes inhibit the fungal growth only partially. This communication is the first report of transformation of a keto-group to an ester group catalyzed by a metal complex. [ABSTRACT FROM AUTHOR]

Magnetite powder was synthesized via chemical co-precipitation method using FeCl3 · 6H2O and FeCl2 · 4H2O as salts and ammonium hydroxide (25% NH4OH) solution as precipitating agent. The phases, composition and morphology of the magnetite was characterized by X-ray diffraction (XRD), micro laser Raman spectroscopy and scanning electron microscopy–energy dispersive X-ray spectroscopy. The XRD and Raman studies confirmed the formation of magnetite phase only. The results showed that the particles were properly crystallized with no other impurity. Very fine and non-uniform powder sizes were observed even after sieving operation. The magnetite particles were also characterized after sintering the powder at 1100°C, grinding and sieving. The resultant powder size in the range of 105–125 µm was obtained. After sintering, magnetite peaks got sharpened due to increase in the crystallite size. Raman peaks even at a higher laser power were observed for magnetite that were absent before sintering. Hematite peaks observed for the un-sintered powder at higher laser power was attributed to oxidation by laser radiation/heat. Efficiency of the co-precipitation process (before sintering) was established to be ∼85%. [ABSTRACT FROM AUTHOR]

Nanocrystalline TiO 2 particles were prepared to study the calcination temperature dependent phase transformation. X-ray diffraction (XRD) patterns showed the strong Bragg peaks correspond to anatase (1 0 1) and rutile (1 1 0) phases with their crystallite size 12 and 49 nm for the samples T1 and T2 calcined at 450 and 700 °C respectively. Raman spectroscopy investigation showed the phase transformation with the dominating rutile peaks from the pure-anatase phase. By UV–vis absorption spectroscopy, the strong ultraviolet-light absorption below 400 nm was observed. Using Kubelka-Munk function, the estimated band gap values were found to be 3.38 and 3.03 eV. The transmission scanning microscopy (TEM) images exhibited the slightly agglomerated nanoparticles while the selected area diffraction (SAED) patterns endorsed the polycrystalline nature. [ABSTRACT FROM AUTHOR]

SrAl2O4Eu2+ green-light emitting powder phosphor was prepared within a few minutes at furnace temperature as low as 550 °C by using combustion method. The prepared powder was characterized by X-ray diffraction, scanning electron microscopy and Fourier-transform infrared spectrometry. Several ESR lines are exhibited by the phosphor, and some are seen in the low field region apart from lines in the g ~ 2.0 region. Crystal fields that were relatively strong arose from distortions close to the Eu2+ ion lead to lines in the low field region. The photoluminescence of Eu2+-activated SrAl2O4 shows a green-emission dominant peak around 514 nm, which can be attributed to the 4f65d1 → 4f7 transition of Eu2+ ions from the synthesized phosphor particles at an excitation wavelength of 345 nm. [ABSTRACT FROM AUTHOR]

The present paper reports the effect of sintering temperature on the properties of Fe–SiC metal matrix nanocomposites (5 wt% SiC; 95 wt% Fe) prepared by powder metallurgy technique. Samples were synthesized by ball milling followed by compaction and then sintering in the temperature interval of 900 – 1100℃ for 3 h, respectively. X-ray diffraction, microstructure, density, hardness, wear and corrosion of prepared samples have been investigated. X-ray diffraction studies show the presence of iron (Fe) and silicon carbide (SiC) along with the presence of iron silicate (Fe3Si) phase. Iron silicate is formed as a result of reactive sintering between iron and silicon carbide particles. Scanning electron microscopy of the samples shows the dispersion of SiC in the whole Fe matrix. Density, hardness, wear and corrosion characteristics of the samples were investigated which varies for different sintering temperature interval. It is expected that the results of this paper will be helpful in developing metal matrix nanocomposites for various industrial applications. [ABSTRACT FROM AUTHOR]

Silver complex of sulfapyridine has been synthesized and characterized by IR, NMR and PL. The crystal structure has been determined by X-ray diffraction technique. Silver complex of sulfapyridine with secondary ligand pyridine crystallizes in monoclinic space group P21/n with lattice parameter: a = 17.8075(4)Å, b = 10.7885(3)Å, c = 17.8075(4)Å, β = 94.12(1)Å and Z = 4. To study the nature of intermolecular interactions and their quantitative contributions towards the crystal packing, Hirshfeld surfaces and accordingly the fingerprint plot analysis have been performed. Molecular properties such as NBO analysis, Homo-Lumo energy calculation have been carried out by DFT method. Furthermore, the antimicrobial activity of silver complex of sulfapyridine and free ligand is studied by the dilution method. [ABSTRACT FROM PUBLISHER]

CeO:M (Eu, Er and Dy) phosphors were synthesized by modified solid-state reaction technique at variable concentrations of Eu, Er and Dy. This technique is suitable for large-scale production and it is less time-consuming. The prepared samples were characterized by X-ray diffraction (XRD) technique, scanning electron microscopy (SEM), and Photoluminescence (PL) decay curve analysis. XRD patterns of the prepared samples confirm the cubic fluorite crystal structure of all phosphors. Crystallite size was calculated by using well known Scherer's formula. SEM images express good surface morphology with nanoflower like shape. Comparative studies of photoluminescence decay curves of CeO:M (Eu, Er and Dy) with different concentrations of dopant have been done. Decay constants for all prepared phosphors were calculated by curve fitting technique. Samples were excited under UV radiation for few nanoseconds at room temperature. The PL decay curves were measured for D→F transition of CeO:Eu,S→I transition of CeO:Er and F→H transition of CeO:Dy phosphors. Decay curve for CeO:Eu (1.5 mol%) phosphor shows optimum concentration with higher intensity of photoluminescence signals and comparatively higher decay constants. [ABSTRACT FROM AUTHOR]

Luminescence behaviour was displayed by dysprosium (Dy) doped BaTiO phosphor which was synthesized via solid state reaction method. The method is suitable for large scale production and useful for production of micron size phosphor. The sample was characterized by X-ray diffraction technique and crystallite size was calculated using Scherer's formula. Effects of optimized concentration of Dy on its thermoluminescence glow curve analysis were carried out for γ irradiation. For fixed concentration of dysprosium ions the TL glow curve was recorded using 6.7 °C s heating rate. Also for variable γ dose 1-2.5 kGy and optimized concentration of dysprosium ion i.e. 4 mol% were carried out. It is found that TL glow curve shows linear response with γ dose. Kinetic parameters were calculated using computerized glow curve deconvolution technique. Photoluminescence study of Dy doped BaTiO phosphor was carried out and it is found that the PL emission spectra in visible region had blue, green and red emission wavelength. CIE coordinate shows color rendering index and correlated color temperature for white light emission of Dy doped BaTiO phosphor. It may be used for visible light emission in display device applications and TL dosimetric applications. [ABSTRACT FROM AUTHOR]

Polycrystalline ceramics with chemical formula BaBiTiO, Pb BiTiO and SrBiTiO have been synthesized using co-precipitation route. In the present study optimization of calcination and sintering temperature is carried out and the relationship between sintering temperature and morphology, dielectric, and ferroelectric properties of the as-prepared samples is extensively investigated. Pellets of these samples were sintered at a range of temperatures 850, 950 and 1050 °C for 2 h. The phase formation of compounds calcined at different temperatures was studied using X-ray diffraction and scanning electron microscopy was used to examine the surface morphology. Crystallite and grain size was seen to increases with an increase in the calcination and sintering temperature respectively. The dielectric and ferroelectric properties of the ceramics were found to improve at a higher sintering temperature. [ABSTRACT FROM AUTHOR]

The utilization of substrate bias voltage to accelerate the sputtered ions in sputtering plasmas is an effective way to alter the properties of coating. In this work, hard nanocrystalline ZrWN coatings were sputter-deposited at relatively low deposition temperature (200 °C) by varying the substrate bias voltage from − 20 V to − 120 V. The effect of negative substrate bias on the microstructure and mechanical properties of nanocrystalline ZrWN coatings has been studied in detail employing X-ray diffraction, field emission scanning electron microscopy, energy dispersive x-ray spectroscopy, atomic force microscopy, transmission electron microscopy, nano-indentation and micro-indentation. The results indicate that the microstructure and morphology were significantly altered as a function of the increasing bias voltage. The bias voltage of − 20 V to − 60 V lead to enhanced ion current density and deposition rate while the resputtering effect was induced as the bias voltage increased beyond – 60 V. A dense glassy structure along with a maximum compressive stress (8 GPa) and hence optimum mechanical properties (hardness ~ 34 GPa, reduced elastic modulus E r ~ 145 GPa, wear resistance ~ 0.23 and fracture toughness ~ 2.25 MPa √ m ) were obtained in the ZrWN nanocrystalline coatings at a bias voltage of − 100 V. The results demonstrate that the enhancement of mechanical properties in ZrWN coatings can be achieved by carefully controlling the processing conditions, which in turn facilitate controlling the microstructure evolution, stress and mechanical properties. [ABSTRACT FROM AUTHOR]

The NaYF 4 phosphors codoped with Er 3+ -Yb 3+ have been synthesized by hydrothermal method using oleic acid as a chelating agent. The crystal structure and surface morphology has been identified with the help of powder X-ray diffraction (PXRD) and field emission scanning microscopy (FE-SEM) technique, respectively. The presence of different functional groups in the developed phosphors have been analyzed by using the Fourier transform infrared spectroscopy (FTIR) technique. The optical non-linear behavior of the prepared phosphors has been performed by using the excitation at 980 nm from a CW diode laser. The effect of Li + ions tri-doping on the structural and luminescence behavior of the Er 3+ -Yb 3+ codoped NaYF 4 phosphors has been discussed suitably. The effect of variation of pump power density on the UC emission intensity of different bands has been investigated. The optical temperature sensing behavior based on the green UC emissions of the Er 3+ -Yb 3+ -Li + tri-doped NaYF 4 phosphors under the excitation at very low pump power density (∼0.32 W/cm 2 ) has been studied. The results obtained from the present study indicate that the Er 3+ -Yb 3+ -Li + tri-doped NaYF 4 phosphors may be of particular interest in developing the NIR to visible upconverters, green display devices and temperature sensors. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis of pure and Cr-doped TiO 2 nanoparticles with different doping concentrations by using a cost-effective solvothermal method. The as-synthesized nanoparticles were characterized by using X-ray diffraction, transmission electron microscopy and UV–Vis spectroscopy to study their structural and optical properties. The XRD pattern showed the prepared material is pure anatase of the crystalline phase. Using TEM measurement, the average particles size is found to be about 11–13 nm while selective area electron diffraction (SAED) patterns have confirmed the polycrystalline nature of the nanoparticles. The size of the crystallite is observed to be decreased with an increase in dopant (Cr) concentration. UV–Vis absorption spectra showed enhanced absorption in the visible range in accordance with the doping concentration of Cr with a red shift in the absorption edge. The band gap energy of doped nanoparticles decreases in accordance with an increase in dopant concentration due to the reduced particles size. This presented work would be useful to tune the optical properties of doped and undoped metal oxide TiO 2 for its optoelectronic applications. [ABSTRACT FROM AUTHOR]

The scale-up synthesis of nZVI (zero-valent iron nanoparticles) was optimized by response surface modeling (RSM). The synthesized nZVI was employed for synergistic degradation of metronidazole (MNZ) or methyl orange (MO) in the presence of sodium borohydride (NaBH 4 ). Key parameters such as initial MNZ or MO concentration, nZVI concentration, and NaBH 4 concentration for MNZ or MO removal process was optimized using central composite design (CCD). Under the optimized conditions (nZVI concentration: 150 mg/L; NaBH 4 :0.1 M; interaction time: 25 min for MNZ and 30 min for MO; and MNZ or MO initial concentration: 40 mg/L), the removal was synergistically increased to 100% (MNZ) and 98.07 ± 1.1% (MO). When nZVI was applied without NaBH 4 , the removal of MNZ and MO were 50.62 ± 0.28 and 43.72 ± 0.29%, respectively. In the presence of NaBH 4 alone, the removal of MNZ or MO was 6.5 ± 1.1% and 4.2 ± 0.7%, respectively. Addition of NaBH 4 was found to enhance the remediation ability of nZVI. The MNZ or MO degradation followed pseudo–first–order kinetics. The degradation mechanism was studied by UV–visible spectroscopy, XRD, SEM-EDX, FT-IR, and BET analyses. The applicability of the process was tested with MNZ-spiked or MO-spiked lake water and ground water samples. [ABSTRACT FROM AUTHOR]

Behavior is displayed by samarium-doped LaAlO3 phosphor which was synthesized by solid state reaction method. For the synthesis of LaAlO3 with variable concentration of Sm (0.2–2.5 mol%) phosphor was calcinated at 1000 °C and sintered at 1250 °C following intermediate grinding. Synthesized sample was characterized by X-ray diffraction analysis and crystallite size was calculated by Scherer's formula. From photoluminescence (PL) spectra of prepared phosphors show broad excitation peak at 250 nm and emission at 566, 600, and 608 nm is obtained. The phosphor is prepared by high temperature synthesis method. Two peaks are obtained in the thermoluminescence (TL) glow curve for lower concentration of Samarium. Single prominent peak is obtained with further increase in the concentration of dopant. It is characteristic yellow-orange emission for samarium ion. The excitation spectra of LaAlO3:Sm3+ phosphor mainly consists of the charge transfer band (CTB) of Sm3+ located in 220–340 nm centered at 250 nm. The present phosphors can act as single host for yellow-orange-red light emission in display devices. The CIE coordinates were calculated by spectrophotometric method using the spectral energy distribution of the LaAlO3 :Sm3+ sample. TL glow curve was recorded for variable concentration of dopant with fixed UV exposer time (20 min) and fixed heating rate (5 °C·s−1). TL glow curve shows broad peak and kinetic parameters are calculated by computerized glow curve deconvolution technique. It is suggested that from TL glow curve analysis prepared phosphor may be useful for TL dosimetric application for UV exposure. [ABSTRACT FROM PUBLISHER]

Near UV-blue emission from cerium ion percentage of ZrO2 phosphor was reported in the manuscript. The samples were prepared by combustion synthesis technique which is suitable for less time taking techniques. Starting material for sample preparation are Zr(NO3)3 and Ce(NO3)3 and urea used as a fuel. Here the variable percentage of cerium ion was (0.1 to 2.5 mol%) used. The prepared sample was characterized by X-ray diffraction analysis for structural analysis and it is found the cubic structure also crystallite size were calculated by Scherer's formula. Morphology and particle size of prepared sample for optimized concentration of cerium was analyzed by field emission gun scanning electron microscopy and high resolution transmission electron microscopy technique. All prepared phosphor with variable concentration of Ce3+ (0.1 to 2.5 mol%) was studied by photoluminescence analysis and it is found that the excitation spectra of prepared phosphor shows broad excitation centred at 396 nm (near UV-blue region). The emission spectra with variable concentration of Ce3+ show strong peaks at 447 nm (blue region). Spectrophotometric determinations of peaks are evaluated by Commission Internationale de I’Eclairage (CIE) technique. Using this phosphor, the desired CIE values including emissions throughout the violet (396 nm) and intense blue (427 nm) of the spectra were achieved. Efficient blue light emitting diodes (LEDs) were fabricated using Ce 3+ doped phosphor based on near ultraviolet excited LED lights. Also the prepared phosphor was useful for sensing application such as biological and chemical sensing. [ABSTRACT FROM PUBLISHER]

Abstract: Single crystal gallium antimonide substrate was implanted with 200 keV iron ions with different ion fluences varying from 1×1014 to 1×1016 cm−2. Optical and structural properties have been investigated using the micro-Raman, Fourier transform infrared and grazing-angle X-ray diffraction measurements. Raman studies have shown the amorphization of gallium antimonide at higher fluences. Fourier transform infrared transmission studies over photon energy range 0.3 to 0.7 eV showed the change in the value of optical density over the entire photon energy range for the implanted samples as compared with the non-implanted sample. Damage profile probed by etching the sample was found to be non-uniformly distributed in the implanted sample. Grazing-angle X-ray diffraction spectra recorded at 1, 5 and 10° suggests the presence of defects and disorder in gallium antimonide after implantation. [Copyright &y& Elsevier]

Abstract: Indium phosphide samples were irradiated with swift (100 MeV) 56Fe7+ ions with different fluences varying from 5×1012 to 2×1014 ions cm−2 at room temperature. Atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques have been used to investigate the irradiation effects. Atomic force microscopy observations revealed the presence of hillocks surrounded with valleys in all irradiated samples. The shape, size and height of the hillocks were found to vary with respect to ion fluences. Root mean square surface roughness was found to change from 0.33 nm to 7.49 nm. X-ray diffraction studies revealed increase in the amount of disorder in the irradiated samples as ion fluence increases. [Copyright &y& Elsevier]

The behavior displayed by photoluminescence and thermoluminescence of BaTiO{3} phosphor activated by samarium ion reported in the manuscript. Sample was prepared by solid state reaction method with calcination temperature 600 ^\circC and sintered at 950 ^\circC. The prepared sample was characterized by X-ray diffraction analysis and matched with COD card number using Celref V3 software. Samarium concentration was fixed i.e., 1 and 1.5 mol% for synthesis. Photoluminescence excitation and emission spectra were recorded and intense peak found at yellow region which shows the transition of samarium ion. Spectrophotometric determination was recorded by CIE technique and it shows the color rendering index of prepared phosphor. For Thermoluminescence glow curve analysis sample was irradiated by gamma dose 0.5–2 kGy using Co^60gamma source. It shows intense broad TL glow curve at 185 ^\circC with a high temperature shoulder peak at 221 ^\circC. It shows a greater number of traps generated in the prepared sample. The associated peak in the broad TL glow curve was separated by the CGCD technique. Kinetic parameters are calculated by the peak shape method using the CGCD technique. [ABSTRACT FROM PUBLISHER]

Gadolinium-doped Y2O3 nanophosphor was synthesized by a solid-state reaction method, which could be used for large-scale production of phosphors. The structure of the phosphor sample was characterized by powder X-ray diffraction, field emission gun scanning electron microscopy and high-resolution transmission electron microscopy. The particle size was calculated from Scherer's formula. X-ray diffraction showed a grain size of 35-55 nm, in good agreement with the scanning electron microscopy image. The synthesized sample showed good morphology and connectivity, with grains and formation of a nano-sized prepared sample. The diffraction pattern was measured by transmission electron microscopy with a selected area diffraction pattern. The prepared phosphor was also examined by thermoluminescence; to record the glow curve, 1 mg phosphor was irradiated with ultraviolet at 254 nm at a fixed heating rate of 7 °C s−1. The sample showed a well-resolved peak at 99 °C for 1 mol% of Gd3+. A lower temperature peak showed less stability and more fading of the prepared sample. A thermoluminescence glow curve gives information about trapping parameters such as activation energy and trap depth, order of kinetics and frequency. All the kinetics were calculated by the peak shape method. [ABSTRACT FROM AUTHOR]

CeO{2}:Dy^3+ phosphors were synthesized by modified conventional solid-state reaction method. The formation of a CeO{2} structure is confirmed via XRD studies. The luminescence measurement upon excitation in ultraviolet and visible range shows the characteristics Dy^3+ excitation and emission. The occurrence of charge transfer band is explained in detail. The emission spectrum of Dy ions consists mainly of several groups of lines in the 450–625-nm region, due to the transitions from the ^4F{9/2}-{6}H{15/2} (blue emission) and the ^4F{9/2}-{6}H{13/2} (yellow emission) of Dy ions. The phenomena of concentration quenching are explained on the basis of electron phonon coupling and multipolar interaction. Different spectral parameters are calculated via the Judd Ofelt approach. The purity of the white light emission is also examined, and it makes Dy^3+ doped CeO{2} a promising candidate for applications in displays and optical device. [ABSTRACT FROM PUBLISHER]

Indium phosphide sample was irradiated with 200 MeV Ag9+ions for the fluence of 2 × 1013 ions cm−2. The sample was chemically etched down up to 240 nm depth to investigate the distribution of defects at different regions. Raman scattering and glancing incidence X-ray diffraction spectra were recorded at different depths. The stress estimated from Raman shift was found to increase with depth up to 160 nm and thereafter it decreased and at a depth of 224 nm sample did not show any stress. Phonon coherence length estimated from the Phonon Confinement Model was found to vary between 43 and 18 nm with respect to depth. Glancing incidence X-ray diffraction results revealed the decrease in crystallite size from 16.12 to 1.00 nm in different depth regions. [ABSTRACT FROM PUBLISHER]

The present paper reports the synthesis, photoluminescence (PL), and thermoluminescence (TL) studies of Eu-doped yttrium oxide (YO) phosphor using inorganic materials like YO, flux calcium fluoride, and europium oxide. The sample was prepared by the modified solid state reaction method, which is the most suitable for large-scale production. The prepared phosphor sample was characterized using powder X-ray diffraction, field emission gun scanning electron microscopy, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy , PL, TL, and Commission Internationale de I'Eclairage techniques. The PL emission was observed in the range 417-632 nm ranges all visible regions for the YO phosphor doped with Eu. Excitation spectrum found at 254 nm. Sharp intense peaks found around 467, 534, 594, 612, and 632 nm with high intensity. From the XRD data, using the Scherer's formula, the calculated average crystallite size of Eu-doped YO phosphor is around 45 nm. TL study was carried out for the phosphor with UV irradiation. The present phosphor can act as single host for white light emission in display devices. [ABSTRACT FROM AUTHOR]

In this paper we review the luminescence properties of Pr-doped CaTiO phosphors, the different methods of sample preparation, and characterization of the materials by use of different techniques, for example X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermo-gravimetric analysis, and atomic force microscopy. Solid-state, sol-gel (SG), and combustion methods are most often used for preparation. The high calcining temperature of the solid-state method can be reduced by addition of rare earth oxides (lanthanide series) LnO and LuO. By use of tetra- n-butyl titanates and calcium nitrates as raw material in the modified solid-state method the luminous properties of samples can be optimized at lower sintering temperatures (600 °C) in less time. SG procedures lead to substantial reinforcement of red photoluminescence intensity so can be regarded as the best technique for phosphor preparation. [ABSTRACT FROM AUTHOR]

The homometallic hexameric ruthenium cluster of the formula [RuIII6(μ 3-O)2(μ-OH)2((CH3)3CCO2)12(py)2] ( 1) (py=pyridine) is solved by single-crystal X-ray diffraction. Magnetic susceptibility measurements performed on 1 suggest that the antiferromagnetic interaction between the RuIII centers is dominant, and this is supported by theoretical studies. Theoretical calculations based on density functional methods yield eight different exchange interaction values for 1: J1=−737.6, J2=+63.4, J3=−187.6, J4=+124.4, J5=−376.4, J6=−601.2, J7=−657.0, and J8=−800.6 cm−1. Among all the computed J values, six are found to be antiferromagnetic. Four exchange values ( J1, J6, J7 and J8) are computed to be extremely strong, with J8, mediated through one μ-hydroxo and a carboxylate bridge, being by far the largest exchange obtained for any transition-metal cluster. The origin of these strong interactions is the orientation of the magnetic orbitals in the RuIII centers, and the computed J values are rationalized by using molecular orbital and natural bond order analysis. Detailed NMR studies (1H, 13C, HSQC, NOESY, and TOCSY) of 1 (in CDCl3) confirm the existence of the solid-state structure in solution. The observation of sharp NMR peaks and spin-lattice time relaxation (T1 relaxation) experiments support the existence of strong intramolecular antiferromagnetic exchange interactions between the metal centers. A broad absorption peak around 600-1000 nm in the visible to near-IR region is a characteristic signature of an intracluster charge-transfer transition. Cyclic voltammetry experiments show that there are three reversible one-electron redox couples at −0.865, +0.186, and +1.159 V with respect to the Ag/AgCl reference electrode, which corresponds to two metal-based one-electron oxidations and one reduction process. [ABSTRACT FROM AUTHOR]

Thermal stability and mechanical properties of zirconium tungsten nitride (Zr–W–N) thin films have been studied. Nano-structured Zr–W–N thin films have been deposited on Si (100) substrates by reactive magnetron sputtering at varying substrate temperatures Ts (100°–600°C). For 100°C≤Ts ≤600°C, X-ray diffraction patterns of the films show a crystalline fcc phase with (111) and (200) preferred crystallographic orientations of grains. Maximum wear resistance (H/Er ~0.22) and maximum resistance to fatigue fracture (H3/Er 2 ~1.0GPa) have been obtained for the film deposited at Ts =400°C. Post annealing of the films deposited at 400°C has been carried out in air from 100°–600°C. Oxygen starts to be incorporated at 300°C and films begin to peel off above 400°C due to increase in oxygen incorporation. Hardness and elastic modulus of annealed films increase with increasing strain. [ABSTRACT FROM AUTHOR]

The present paper reports the thermoluminescence (TL) glow curve of Eu-activated SrAlO phosphor with different UV exposure times. Evaluation of kinetic parameters was done by the peak shape method. The recorded glow curve shifts towards lower temperatures with respect to increasing UV exposure time. The peaks were found at 146.76, 141.34 and 140.37 °C, respectively, for 5, 10 and 15 min of UV exposure using the heating rate of 3°C s. The glow peak shows the second-order kinetics. Different kinetic parameters, i.e. trap depth, order of kinetics, activation energy, and frequency factor are also calculated. The XRD pattern of the sample is compared with reported XRD using the software match. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this work is to develop hydrophobic coatings for outdoor insulators using sputtering technique. Hafnium oxide is characterized by high dielectric constant, large band gap (5.6eV), high refractive index (2.1) and good mechanical, thermal and chemical properties. Hence HfO2 is suitable as a protective coating for outdoor insulators used in the transmission line and transformers. Hafnium oxide coatings were deposited on glass substrates by DC magnetron sputtering technique at a sputtering pressure of 5mTorr, 10mTorr, 15mTorr, 20mTorr and 25mTorr. The deposited films were characterized by techniques like X-ray diffraction (XRD), atomic force microscopy (AFM), water contact angle goniometry and UV–vis-NIR spectrophotometer. The average crystallite size calculated from XRD peaks shows that it increases with increase in sputtering pressure up to 15mTorr and then it starts decreasing. The roughness calculated from AFM images shows the similar trend. The deposited films were found to be hydrophobic and transparent. The hydrophobicity of the films was correlated with the roughness calculated from AFM. The effect of sputtering pressure was also investigated on optical band gap and refractive index calculated from transmission and absorption data. The electrical resistivity was found to be high, thus ensuring insulating property of the deposited films. [Copyright &y& Elsevier]

A lead-resistant bacteria isolated from soil contaminated with car battery waste were identified as Providencia alcalifaciens based on biochemical characteristics, FAME profile and 16S rRNA sequencing and designated as strain 2EA. It resists lead nitrate up to 0·0014 mol l−1 by precipitating soluble lead as insoluble light brown solid. Scanning electron microscopy coupled with energy-dispersive X-ray spectrometric analysis (SEM-EDX) and X-ray diffraction spectroscopy (XRD) revealed extracellular light brown precipitate as lead orthophosphate mineral, that is, Pb9 (PO4)6 catalysed by phosphatase enzyme. This lead-resistant bacterial strain also demonstrated tolerance to high levels of cadmium and mercury along with multiple antibiotic resistance. Providencia alcalifaciens strain 2EA could be used for bioremediation of lead-contaminated environmental sites, as it can efficiently precipitate lead as lead phosphate. Significance and Impact of the Study Providencia alcalifaciens strain 2EA resist lead nitrate up to 0·0014 mol l−1 by precipitating soluble lead (Pb+2) as insoluble light brown solid. Scanning electron microscopy coupled with energy-dispersive X-ray spectrometric analysis (SEM-EDX) and X-ray diffraction spectroscopy (XRD) revealed extracellular light brown precipitate as lead orthophosphate mineral, that is, Pb9 (PO4)6 catalysed by phosphatase enzyme. Providencia alcalifaciens strain 2EA could be used for bioremediation of lead-contaminated environmental sites, as it can efficiently precipitate lead as insoluble lead phosphate. [ABSTRACT FROM AUTHOR]

Cadmium Telluride (CdTe) thin films grown by thermal evaporation on quartz substrates were irradiated with swift (100 MeV) Ni+4 ions at various fluences in the range 1011 - 1013 cm -2. The modification in structure and surface morphology has been analyzed as a function of fluence using XRD and AFM techniques. The XRD showed a reduction in peak intensity and grain size with increasing fluence. The AFM micrographs of irradiated thin films show small spherical nanostructures. In addition to direct imaging, AFM profile data enable to derive the Power Spectral Density (PSD) of the surface roughness. In the present work PSD spectra computed from AFM data were used for studying the surface morphology of films. The PSD curves were fitted with an appropriate analytic function and characteristic parameters were deduced and discussed in order to compare film morphology with varying fluence levels. [ABSTRACT FROM AUTHOR]

The present article demonstrates how the stiffness, hardness as well as the cellular response of bioinert high-density polyethylene (HDPE) can be significantly improved with combined addition of both bioinert and bioactive ceramic fillers. For this purpose, different amounts of hydroxyapatite and alumina, limited to a total of 40 wt %, have been incorporated in HDPE matrix. An important step in composite fabrication was to select appropriate solvent and optimal addition of coupling agent (CA). In case of chemically coupled composites, 2% Titanium IV, 2-propanolato, tris iso-octadecanoato-O was used as a CA. All the hybrid composites, except monolithic HDPE, were fabricated under optimized compression molding condition (140°C, 0.75 h, 10 MPa pressure). The compression molded composites were characterized, using X-ray diffraction, Fourier transformed infrared spectroscopy, and scanning electron microscopy. Importantly, in vitro cell culture and cell viability study (MTT) using L929 fibroblast and SaOS2 osteoblast-like cells confirmed good cytocompatibility properties of the developed hybrid composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

The misfolding and aggregation of the intrinsically disordered, microtubule-associated tau protein into neurofibrillary tangles is implicated in the pathogenesis of Alzheimer's disease. However, the mechanisms of tau aggregation and toxicity remain unknown. Recent work has shown that anionic lipid membranes can induce tau aggregation and that membrane permeabilization may serve as a pathway by which protein aggregates exert toxicity, suggesting that the plasma membrane may play dual roles in tau pathology. This prompted our investigation to assess tau's propensity to interact with membranes and to elucidate the mutually disruptive structural perturbations the interactions induce in both tau and the membrane. We show that although highly charged and soluble, the full-length tau (hTau40) is also highly surface active, selectively inserts into anionic DMPG lipid monolayers and induces membrane morphological changes. To resolve molecular-scale structural details of hTau40 associated with lipid membranes, X-ray and neutron scattering techniques are utilized. X-ray reflectivity indicates hTau40s presence underneath a DMPG monolayer and penetration into the lipid headgroups and tailgroups, whereas grazing incidence X-ray diffraction shows that hTau40 insertion disrupts lipid packing. Moreover, both air/water and DMPG lipid membrane interfaces induce the disordered hTau40 to partially adopt a more compact conformation with density similar to that of a folded protein. Neutron reflectivity shows that tau completely disrupts supported DMPG bilayers while leaving the neutral DPPC bilayer intact. Our results show that hTau40s strong interaction with anionic lipids induces tau structural compaction and membrane disruption, suggesting possible membrane-based mechanisms of tau aggregation and toxicity in neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

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