MoO3 Content Research Articles

РОЛЬ КОМБІНОВАНИХ СОЛЬОВИХ РОЗПЛАВІВ У СИНТЕЗІ ПОДВІЙНОГО ОРТОФОСФАТУ НАТРІЮ-ЦЕРІЮ(ІІІ)

The efficient crystallization conditions for high temperature synthesis of sodium-cerium(III) orthophosphate from binary molten salts have been investigated in a light of influence of the inert reaction media addition. Taking into consideration NaF and Na2MoO4 as an addictives to a convention phosphate melt the crystallization regions of CePO4 and Na3Ce(PO4)2 have been identified by means of IR spectroscopy and powder X-Ray diffraction methods. The initial Na/P ratio in the melt has been shown to play the key role in pure Na3Ce(PO4)2 phase formation. The concentration of NaF has been chosen as 20–60 mol. % and MoO3 in a range of 30–60 mol. %, while the cerium(III) content has been maintained equal to 10 mol. %. Additional application of NaF or Na2MoO4 lowers the temperature from 1400 in comparison to Na4P2O7 flux to 1000°C and homogenization time from 12 to 1h., respectively. Thus, the optimal conditions for the high-temperature growth has been found to be Na/P = 1.67 and NaF content equal to 30–45% mol. in case of fluoride-containing systems, and Na/P> 4,00 with MoO3 content of 25–36% mol for a molybdate one. In case of both fluoride and molybdate addition the crystallization region of the target compound has been bordered by a wide area of CePO4 phase. Three crystallization regions has been estimated during crystallization process: CePO4, Na3Ce(PO4)2 and a wide field of their co-crystallization. With Na/P ratio in the binary melt there is a simultaneous change in the solids structure prepared. Thus, when CePO4 possesses highly condensed CeO8 polyhadra in the framework and crystallizes at lower Na/P ratio, Na3Ce(PO4)2 corresponds to isolated CeO8 moieties that are stabilized under higher Na/P values. Within the synthetic conditions investigated, the melts have shown to play a depolymerizing role for the phosphate chains found in the melt, leading to crystallization temperature lowering in initial melt. The approach proposed for the of Na3Ce(PO4)2 synthesis allows to expand the temperature range of its formation and to carry out its uniform doping with fluorescent activators to modify its characteristic spectrum for the needs of modern inorganic LEDs.

Investigation of optical properties about Rubrene:MoO3 film

Rubrene:MoO3 mixed films(in 1:1 wt ratio) were deposited on quartz substrates using the thermal evaporation technique and the absorption spectrum of the mixed film was measured. The results demonstrate that the mixed film shows intensively absorption at the near-infrared region(∼930 nm) which indicates that the interaction between Rubrene and MoO3 is intensively and induced intermediate level in the band gap of Rubrene and formed charge-transfer complex(CTC). Furthermore, the type of transition is direct allowed transition according to the measurement of optical band gap. To further analysis the affection of MoO3 to Rubrene, the Rubrene:MoO3 films with different proportion of MoO3 were also prepared using the thermal evaporation technique. The absorption spectrum of the mixed films was measured and the results demonstrate that the interaction between Rubrene and MoO3 is enhancing with the concentration of MoO3 increasing and the energy needed by the transition of electrons is decreasing.The near-infrared photo-detection device based on Rubrene:MoO3 film was fabricated. The current-voltage(I–V) characteristic of the device was measured and the results demonstrate that under 5 V bias, the infrared detector exhibits an Iphoto/Idark ratio of ∼8 under a 940 nm light illumination with a light intensity of 0.5 W·cm−2.

SURFACE PASSIVE FILM CHARACTERISTIC OF Q235 CARBON STEEL IN PURE MOLYBDATE SOLUTION

In pure Na2MoO4solutions with different concentrations of MoO[Formula: see text] (0.01, 0.04, 0.06, 0.08 and 0.10 mmol/L), a passive film was formed on the surface of Q235 carbon steel spontaneously, and the influences of MoO[Formula: see text] concentrations on the passive film characteristics were investigated. The electrochemical and microstructural techniques of electrochemical impedance spectroscopy (EIS), Mott–Schottky plot (MSP), scanning electron microscope (SEM) and X-ray photoelectron spectroscope (XPS) were applied to characterize the passive film characteristics, including resistance, defect, microstructure and composition. The resistance and defect of passive film respectively increased and decreased with increased MoO[Formula: see text] concentration up to 0.08[Formula: see text]mmol/L, which was the critical MoO[Formula: see text] concentration of complete passivation for the Q235 surface. The passive film formed in the 0.08[Formula: see text]mmol/L Na2MoO4solution showed a dense microstructure and was composed of Fe2(MoO[Formula: see text] mainly. Further, in this work, the relation between characteristic and anti-corrosion of passive film was also discussed.

Flexible Freestanding MoO3-x -Carbon Nanotubes-Nanocellulose Paper Electrodes for Charge-Storage Applications.

Herein, a one-step synthesis protocol was developed for synthesizing freestanding/flexible paper electrodes composed of nanostructured molybdenum oxide (MoO3-x ) embedded in a carbon nanotube (CNT) and Cladophora cellulose (CC) matrix. The preparation method involved sonication of the precursors, nanostructured MoO3-x , CNTs, and CC with weight ratios of 7:2:1, in a water/ethanol mixture, followed by vacuum filtration. The electrodes were straightforward to handle and possessed a thickness of approximately 12 μm and a mass loading of MoO3-x -CNTs of approximately 0.9 mg cm-2 . The elemental mapping showed that the nanostructured MoO3-x was uniformly embedded inside the CNTs-CC matrix. The MoO3-x -CNTs-CC paper electrodes featured a capacity of 30 C g-1 , normalized to the mass of MoO3-x -CNTs, at a current density of 78 A g-1 (corresponding to a rate of approximately 210 C based on the MoO3 content, assuming a theoretical capacity of 1339 C g-1 ), and exhibited a capacity retention of 91 % over 30 000 cycles. This study paves the way for the manufacturing of flexible/freestanding nanostructured MoO3-x -based electrodes for use in charge-storage devices at high charge/discharge rates.

Physical, mechanical and gamma-ray shielding properties of highly transparent ZnO-MoO3-TeO2 glasses

Physical, mechanical and radiation shielding properties of ZnO-MoO3-TeO2 glasses were studied. Density, molar volume, oxygen molar volume, oxygen packing density were evaluated for the interpretation of physical properties. Mechanical properties were determined through Vickers hardness measurements. The shielding estimation was accomplished by studying linear attenuation coefficient (LACμ), mass attenuation coefficient (MAC), effective atomic number (Zeff), effective electron density (Neff), mean free path (mfp), exposure buildup factor (EBF) and energy absorption buildup factor (EABF). The glasses were irradiated by 133Ba radioactive source emitting gamma rays in the range of 79.61 keV to 383.80 keV to determine LACs and MACs. mfp values were calculated for present glasses and compared with various concretes and a commercial window glass in energy region 81–384 keV. The glass structure became stronger and mechanical properties showed an increment with increasing MoO3 content. Synthesized glasses have lower mfp values indicating better shielding properties than concretes and window glass.

Waste recycling of coal fly ash for design of highly porous whisker-structured mullite ceramic membranes

Coal fly ash, a solid state waste massively produced from coal combustion, is considered to be highly hazardous to the environment due to its persistently toxic trace elements. High-value added waste recycling is a promising technique to address this issue. In this work, a waste-to-resource strategy is proposed for design of highly porous whisker-structured mullite ceramic membranes derived from waste coal fly ash and Al(OH)3 as raw materials and MoO3 as a single sintering additive. These were characterized in terms of their dynamic sintering behavior, shrinkage, bulk density, porosity, phase evolution, microstructure, pore size distribution, N2 permeation flux, and mechanical strength. Addition of molybdenum trioxide effectively inhibited the sintering densification of membranes while at the same time forming a metastable low viscosity liquid at lower temperatures. This enables formation of a novel and more highly porous whisker-interlocked structure and accelerates the growth of mullite whiskers with controllable morphologies. Without degradation of mechanical properties, the open porosity increased significantly from 41.65 ± 0.13% to 58.14 ± 0.15% with increasing MoO3 content from 0 to 20 wt.% without any pore-forming agent, while shrinkage and pore size decreased. The method proposed in this study is expected not only to give a new and facile insight for high-value added recycling of waste coal fly ash but also to fabricate low-cost high performance ceramic membranes with novel structures for further environmental applications.

Catalytic performance of NiMo/Al2O3-USY in the hydrocracking of low-temperature coal tar

A series of NiMo/Al2O3-USY catalysts with different MoO3 contents were prepared through incipient wetness method and further modified with NH4F. The NiMo/Al2O3-USY catalysts were characterized by XRD, XPS, HR-TEM, NH3-TPD, H2-TPR and N2 adsorption and their catalytic performance in the hydrocracking of low-temperature coal tar (LTCT) was investigated in a 200 mL fixed-bed reactor. The results indicate that the appropriate MoO3 content is 15%; higher MoO3 content may lead to the agglomeration of active metals on the support, although it has little influence on the sulfidation degree of Mo species and the conversion of coal tar upon hydrocracking. In addition, the amount of strong acid sites and pore diameter decrease gradually with a further increase in the MoO3 content, which is disadvantageous for deep hydrocracking. The modification of USY zeolite with NH4F solution can enlarge the average pore diameter of resultant NiMo/Al2O3-USY catalysts and then improve the residue conversion of coal tar. However, the amount of strong acid sites decreases obviously when the concentration of NH4F solution exceeds 0.6 mol/L, which may lead to an increase of the sulfur content in the hydrocracking product. Over the NiMo/Al2O3-USY catalyst modified with 0.6 mol/L NH4F solution, the residue conversion of coal tar reaches 87.65%; the sulfur contents in the gasoline fraction (< 180°C) and diesel fraction (180–320°C) are 5.96 and 34.98 mg/kg, respectively.

UV detector based on an FTO/TiO2/MoO3 heterojunction with a potential well trapping electrons in the dark

An FTO/TiO2/MoO3 based UV detector has been fabricated through the synthesis of TiO2 nanowires (NWs) on FTO using the hydrothermal method, the preparation of MoO3 on TiO2 NWs by the spin-coating method, after the hydrothermal synthesis, and the preparation of Ag electrodes on the FTO and MoO3. The detector exhibits an excellent performance of photo-to-dark current ratio of more than two orders of magnitude. This performance is produced because the dark current under 2.2 V bias has been significantly inhibited due to the electronic potential well formed by the energy band distribution while the photocurrent has increased in comparison with FTO/TiO2 based detectors under the same conditions which also have a higher photo-to-dark current ratio without the MoO3 content. Not only does this study take advantage of 1D NWs and 2D nanostructures, but it also provides a new way to inhibit the dark current of detectors.

Enhanced sulfur‐resistant methanation performance over MoO3–ZrO2 catalyst prepared by solution combustion method

Sulfur‐resistant methanation of syngas was studied over MoO3–ZrO2 catalysts at 400°C. The MoO3–ZrO2 solid‐solution catalysts were prepared using the solution combustion method by varying MoO3 content and temperature. The 15MoO3–ZrO2 catalyst achieved the highest methanation performance with CO conversion up to 80% at 400°C. The structure of ZrO2 and dispersed MoO3 species was characterized using X‐ray diffraction and transmission electron microscopy. The energy‐dispersive spectrum of the 15MoO3–ZrO2 catalyst showed that the solution combustion method gave well‐dispersed MoO3 particles on the surface of ZrO2. The structure of the catalysts depends on the Mo surface density. It was observed that in the 15MoO3–ZrO2 catalyst the Mo surface density of 4.2 Mo atoms nm−2 approaches the theoretical monolayer capacity of 5 Mo atoms nm−2. The addition of a small amount of MoO3 to ZrO2 led to higher tetragonal content of ZrO2 along with a reduction of particle size. This leads to an efficient catalyst for the low‐temperature CO methanation process.

Physical Investigations on (MoO&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;x&lt;/sub&gt;-(WO&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;1-x&lt;/sub&gt; Composite Thin Films

Thin films of (MoO3)x-(WO3)1-x (x = 0.4, 0.6, 0.8) were deposited on glass and silicon (100) substrates by flash evaporation technique. The purpose of the flash evaporation is to prevent the decomposition of composite into individual species during thin film deposition. The films were deposited at the oxygen partial pressures of 2x10-5, 2x10-4 mbar and substrate temperatures of 150 0C, 350 0C. The deposited films were characterized for their structure by Graging Incidence X-ray Diffraction (GIXRD), microstructure by Field Emission Scanning Electron Microscopy (FESEM), optical property by UVVis spectra. The X-ray diffraction reveals that the (MoO3)x-(WO3)1-x composite thin film crystallizes in orthorhombic and monoclinic phases. At lower oxygen partial pressures of 2x10-5 mbar and lower substrate temperatures of 150 0C the film crystallizes in orthorhombic and tetragonal phases. Whereas at higher substrate temperatures of 350 0C both orthorhombic and monoclinic mixed phases are present. The optical transmittance spectra of the films were recorded in the wavelength range 300-1100 nm. The optical energy gap of the films is 3.05 eV and increases to 3.21 eV with increase in MoO3 concentration. The width of localized states is 0.47 eV and decreasing with increasing MoO3 concentration. The oxide materials in thin film form exhibit the change in the transmittance when exposed to electro magnetic waves (EM) of visible region. In this respect the estimation of color centre concentration will give the information regarding the response of the films to change their transmittance when exposed to EM waves in the visible region. The colourcenter concentration of the films (for x = 0.4) deposited at 150 0C and irradiation time of 120 minutes, is 3.02 x 1017/cm3 and reaches to maximum value of 4.94 x 1017/cm3, (for x = 0.8) when deposited at 350 0C and irradiated for 150 minutes.

Effect of ZnO and MoO3 Addition on Thermal and Mechanical Properties of Tellurite Glasses

In the present study, zinc‐molybdenum‐tellurite glasses are prepared and their thermal, thermo‐mechanical, viscous, and mechanical properties for mid‐IR molded glass lens applications are studied. From the thermal analysis, it is found that the glass transition temperature, onset crystallization temperature, and stability parameters slightly increase with an increase in ZnO content in both series of glasses. Thermal expansion coefficient decreases from 16.56 to 14.67 × 10−6 K−1 as the ZnO content increased from 10 to 30 mol%. For fixed 10 mol% of MoO3 content, Knoop hardness slightly decreases from 3009 to 2842 MPa as ZnO content increases from 10 to 30 mol% whereas it increases for 20 mol% of MoO3. The results indicate that the addition of ZnO and MoO3 contents into the tellurite glass system increases bridging oxygen contribution and in turn network compactness of tellurite matrix.

Structural characterization and electrical conductivity analysis of MoO3–SeO2–ZnO semiconducting glass nanocomposites

A series of glass nanocomposite samples of the general composition formula xMoO3–(1-x) (0.5SeO2–0.5ZnO) for x = 0.05, 0.1, 0.2, and 0.3 have been prepared by solid-state reaction, i.e., slow cooling process. The structural characteristics have been explored by analyzing X-ray diffraction patterns, Fourier-transform infrared, and UV–Vis spectra. The superposition of different nanophases SeO2, SeO3, ZnO, MoO3, Zn (SeO3), Zn (SeO4), Zn(MoO4), Zn2Mo3O8 and ZnMo8O10 over the amorphous glassy matrices have been identified, and their crystallite sizes have been evaluated as well. Fourier transform infrared (FTIR) spectra reveal different types of bonding like Zn–O–Se type and stretching vibrations of MoO6 octahedral units. It is observed that with increasing MoO3 concentration, the estimated values of optical bandgap energy, Urbach energy, and average crystallite size reduce. The dependency of electrical conductivity on frequency and temperature have been analyzed using Almond-West formalism and Jonscher's universal power-law. The non-linear character of DC conductivity and different activation energies at low and high-temperature regions affirm that the present glassy systems exhibit semiconducting nature. Moreover, DC conduction process is due to small polaron hopping through localized or defect states. The decreasing trend of power-law exponent (s) with temperature rise reveals that AC conduction mechanism is consistent with the correlated barrier-hopping (CBH) model. The existing correlated barrier-hopping model has been modified to attain reasonable values of fitting parameters and to obtain theoretical values of ideal thermodynamic glass transition temperature. The AC conductivity activation energy and free energy required for small polaron migration reduce with increasing conductivity. The scaling property emphasizes that conductivity relaxation process is subjected to the structure of the composition and does not depend on temperature.

The role of structural features in heterogeneous catalytic oxidation of H2 on TiO2:MoO3 nanocomposites

TiO2:MoO3 nanocomposites with MoO3 content in the range of 0.1–10 mol.% were synthesized using sol-gel technology. The role of the structural peculiarities of TiO2:MoO3 composite in hydrogen adsorption and catalytic oxidation was discussed. Possibility of the selective oxidation of hydrogen in the presence of methane in the atmosphere was demonstrated.

Structure of xMoO3-(100-x)TeO2 glasses by neutron diffraction and Reverse Monte Carlo modeling

Short-range structural properties of glasses of the system: xMoO3-(100-x)TeO2 (x = 20, 30, 40 and 50 mol%) were studied by neutron diffraction. The diffraction data was modeled by Reverse Monte Carlo (RMC) simulations and the partial pair correlation distributions, Te–O, Mo–O, O–O bond-lengths/distances, Te and Mo speciation and the bond angle distributions were determined. It was found that TeO3, TeO4 and TeO5 are the major structural units and Mo ions exist in triangular, tetra, penta and hexa-units with the dominant fraction being that of MoO4 and MoO5 units in the glass network. Both the Te–O and Mo–O atomic pair distributions show peaks at same distances in the range: 1.97 ± 0.02 to 2.00 ± 0.03 and the Mo–O and Te–O structural units are found to have very similar dimensions and geometry. The O–Te–O and O–Mo–O bond angle distributions have peaks at 88.2°, which confirm that Oeq-Te–Oax are the most abundant Te–O linkages in the glass network. The glasses do not show any systematic variation in the average Te–O and Mo–O co-ordinations on increasing MoO3 concentration from 20 to 50 mol%, due to the dual character of MoO3 as a network modifier and former.

Kinetic and thermodynamic factors controlling the dissolution of molybdate-bearing calcines during nuclear glass synthesis

As part of an ongoing program to constrain the factors affecting phase stability in nuclear waste containment glasses, the thermodynamic and kinetic factors influencing molybdenum oxide solubility in a borosilicate melt have been studied. A simplified system has been chosen to study how Mo oxide is transferred from solid effluent residues (calcines) to glass. The model calcines used are pure Na2MoO4 and a more complex mixture of Na2MoO4 and Al-bearing phases. These solid residues are mixed with a borosilicate glass frit and heat treated isothermally at temperatures in the range 700–1000 °C for times ranging from 2 min to 8 h. The mineralogy of the mixtures has been followed as a function of temperature and time using XRD and 27Al and 23Na MAS NMR spectroscopy, while the structure and composition of the amorphous phase have been studied by 11B MAS NMR and electron microprobe. The results obtained illustrate that while the dissolution of Al-rich calcines can modify the structure of the borosilicate network this does not affect either the MoO3 content of the liquid at saturation, or the characteristic time-scale required to reach saturation. In detail, the variation of the Mo content of the liquid at saturation can be described by an Arrhenian temperature dependence with an activation energy of 30 ± 5 kJ/mol and the time-scale required to reach saturation, can be described by an exponential function of time. This time-scale also shows Arrhenian temperature dependence with an activation energy of 225 ± 25 kJ/mol, a value identical within uncertainty to that associated with viscous flow. Using the experimental results, a numerical model for dissolution along variable temperature-time paths has been developed. These models indicate that for systems that are capable of complete dissolution grain-size is one of the most important parameter controlling the efficiency of the dissolution process.

The structure and properties of cesium loaded Mo-Fe-phosphate glasses

Chemically durable iron phosphate glasses are promising candidates for hosting nuclear wastes containing constituents like Cs2O and MoO3 that have lower solubility in more conventional borosilicate glasses. In this work, two series of Cs-Mo-Fe-phosphate glasses were prepared and characterized. For glasses in Series A (xCs2O∙(100-x)∙(15MoO3∙22.5Fe2O3∙62.5P2O5), x = 0, 7.5, 15.0, 22.5), increasing Cs2O contents increase the molar volume and decrease the glass transition temperature. Raman spectroscopy reveals that adding Cs2O breaks down linkages between MoO6 octahedra, replacing MoOMo and MoO bonds with Mo-O−Cs+ bonds. Phosphate anion chromatography reveals that adding Cs2O has little effect on the phosphate anion distributions. For glasses in Series B (15Cs2O∙ yMoO3∙(28.75-y)Fe2O3∙56.25P2O5, y = 0, 5.75, 11.50, 17.25, 23.00, 28.75), the glass transition temperature decreases and the aqueous dissolution rates increase when MoO3 replaces Fe2O3. The formation of isolated MoO6 octahedra with Mo-O−Cs+ bonds results in an increase in the average phosphate anion-length in the MoO3-rich glasses. Mössbauer spectroscopy indicates that ferric ions dominate in both series, and that the average Fe-coordination number increases with increasing Cs2O content (series A) and with increasing MoO3 content (series B).

Structural, Optical and Electrochromic Property of WO3: MoO3 Thin Film Prepared by RF Magnetron Sputtering Technique

Tungsten oxide (WO3) films have been deposited on glass substrates by RF magnetron sputtering method for different MoO3 concentration. During experiment consternation of MoO3 was varied from 5%, 10% and 15%. We examined the effect of various MoO3 concentration on structural, optical and electrochromic properties of WO3 films. To study, crystal structure and other properties XRD analysis carried out, and we found that the deposited films shows amorphous feature. The optical properties were examined using UV–Visible spectrophotometer using wavelength range 300-900 nm. From the transmittance spectra we found that as the concentration of MoO3 increases the band gap and transmittance value decreases. The electrochromic properties were examined using three electrode electrochemical cell and the potential applied between ±2.2 V. After studying electrochromic property we observed that WO3:MoO3 the films have good coloration and bleaching properties and the maximum value for coloration efficiency was 2.303 mm2/C for 15% MoO3 concentration.

Preparation, optical, and electrical properties of rubrene∶MoO&lt;sub&gt;3&lt;/sub&gt; films

&lt;sec&gt;In this paper, the mixed films with different rubrene-to-MoO&lt;sub&gt;3&lt;/sub&gt; ratios are deposited on the substrates of Si, indium tin oxide and quartz glass by using the thermal evaporation technique. First, these films are characterized by atomic force microscopy and X-ray diffraction in order to identify their surface morphology and their structure properties. The results show that all the films are amorphous and the film has the best flatness when the rubrene-to-MoO&lt;sub&gt;3&lt;/sub&gt; ratio is 2∶1. Second, the optical properties of the mixed films are investigated by both photoluminescence (PL) spectra and absorption spectra. The optical band gap of rubrene and MoO&lt;sub&gt;3&lt;/sub&gt; are 2.2 eV and 3.49 eV respectively and there is almost no absorption about rubrene and MoO&lt;sub&gt;3&lt;/sub&gt; in the near-infrared (NIR) region. However the PL spectrum shows a peak in NIR region and it indicates that the interface between rubrene and MoO&lt;sub&gt;3&lt;/sub&gt; possesses an abrupt discontinuity at the vacuum level, resulting in electron wave functions overlapping and charge-transfer complex (CTC) forming. The intermediate state within the original band gap of rubrene with energy of 1.25 eV is induced by the CTC, which suggests the possibility of charge transfer exciton generated upon NIR excitation. The absorption spectra of the mixed films show that there is an obvious absorption. All the films have the same absorption peak except the film with a rubrene-to-MoO&lt;sub&gt;3&lt;/sub&gt; ratio of 4∶1 and it indicates that the concentration of MoO&lt;sub&gt;3&lt;/sub&gt; has almost no influence on the absorption of the mixed films. The optical band gaps of the mixed thin films are calculated in a spectral range of 345－1035 nm according to the Tauc equation, and the results show that the optical band gap of the film with a rubrene-to-MoO&lt;sub&gt;3&lt;/sub&gt; ratio of 2∶1 is narrowest (~2.23 eV).&lt;/sec&gt; &lt;sec&gt;In order to study the electrical characteristics of the mixed films, an Al/rubrene:MoO&lt;sub&gt;3&lt;/sub&gt;/ITO device is fabricated. The current density-voltage (&lt;i&gt;J&lt;/i&gt;-&lt;i&gt;V&lt;/i&gt;) characteristic is also investigated. The analysis of the &lt;i&gt;J&lt;/i&gt;-&lt;i&gt;V&lt;/i&gt; measurement for the device indicates that the current conduction in the Al/rubrene:MoO&lt;sub&gt;3&lt;/sub&gt;/ITO device is Ohmic type when the rubrene-to-MoO&lt;sub&gt;3&lt;/sub&gt; ratios are 4∶1 and 2∶1, and it is Schottky type when the ratio is other value. The current for rubrene-to-MoO&lt;sub&gt;3&lt;/sub&gt; ratio of 1∶1 is larger than that for 1∶2, which indicates that the contact is better when the surface is more smooth. These properties of the mixed films can result in the applications in the near-infrared region.&lt;/sec&gt;

An investigation on shielding properties of BaO, MoO3 and P2O5 based glasses using MCNPX code

Abstract In the present work, some radiation shielding quantities (mass attenuation coefficients, effective atomic number, effective electron density, half value layer and mean free path) for various BaO–MoO3–P2O5 ternary glass systems have been determined within the 0.015–15 MeV energy range, using WinXCom program. Additionally, the mass attenuation coefficients of all the investigated glasses have been calculated using MCNPX simulation code (version 2.6.0) and compared to those of WinXCom results. Among the studied glasses, BaMoP8 glass sample with MoO3 content of 70% mol is found to have superior gamma-ray shielding characteristics. Moreover, the glasses studied in this paper possess better radiation shielding properties by providing shorter half value layer (HVL) than RS-253 G18 commercial glass and some concrete samples namely ordinary, hematite-serpentine and ilmanite-limonite.

Role of molybdenum ions in lead zinc phosphate glass system by means of dielectric studies

Abstract PbO-ZnF2-P2O5 glasses doped with different mol% (0.1 to 1.0) of MoO3 have been prepared. Dielectric properties ∊′(ω), tanδ, σAC, of the synthesized samples were calculated from frequency measurements versus temperature. Space charge polarization was used to analyze the temperature and frequency dispersions of dielectric constant ∊′(ω) and dielectric loss tanδ. Quantum mechanical tunneling model was employed to explain the origin of AC conductivity. The AC conductivity exhibited an increasing trend with increasing concentration of MoO3 (up to 0.2 mol%) but the activation energy for conduction decreased. The plots of AC conductivity revealed that the relaxation dynamics depends on MoO3 dopant concentration.