Addition Of V2O5 Research Articles

Phase composition, microstructure, and gyromagnetic properties of LiZnTi ferrites sintered at low temperature

In this study, a series of Li0.43Zn0.27Ti0.13Fe2.17O4 ferrites were successfully synthesized by solid-state reaction method at 920 ℃ employing low melting point V2O5 as sintering aid. The X-ray diffraction (XRD) studies demonstrated that all samples exhibited spinel phase. Microscopic image analysis revealed that both the grain growth and uniformity were significantly promoted. The average grain size was increased from 0.65 µm to 4.53 µm when V2O5 was increased from 0.0 wt% to 2.4 wt%. In terms of the magnetic properties, the saturation magnetization (4πMs) of the samples increased from 2915 Gs to 3434 Gs, the coercivity (Hc) decreased from 848.3 A/m to 242.2 A/m, and the ferromagnetic resonance linewidth (ΔH) decreased from 963 Oe to 543 Oe. It could be noted that the proper addition of V2O5 is the key to optimizing the microstructure and magnetic properties of LiZnTi microwave ferrite. Therefore, as an effective additive, V2O5 can promote the development of low temperature co-fired ferrites.

Microwave dielectric properties of V2O5/CeO2 doped (Mg0.95Ca0.05)TiO3‐MgO and their application to a dielectric filter

AbstractThe phase composition, microstructure, sintering characteristics, and microwave dielectric properties of nonstoichiometric MgTiO3‐CaTiO3 ceramics containing an additional 0.2 mol MgO, compositely doped with various amounts of V2O5 and CeO2 additives, were studied. The results revealed that adding an optimum amount of V2O5 and CeO2 could effectively impede second‐phase formation in Mg0.95Ca0.05TiO3‐MgO. High amounts of Mg2+ can react with MgTi2O5 to reduce the content of the secondary phase. The addition facilitated the densification of the microstructure and reduction of sintering temperature. Moreover, the dielectric performances of the material were significantly influenced by V2O5 and CeO2. Mg0.95Ca0.05TiO3‐MgO doped with 0.75 wt% CeO2 exhibited excellent frequency and temperature stabilities. In particular, when co‐doped with 0.5 wt% V2O5 and 0.75 wt% CeO2, Mg0.95Ca0.05TiO3‐MgO exhibited optimum properties after sintering at 1300°C for 2 h; a dielectric constant εr ∼ 19.92 (7 GHz),a Q×f value ∼ 65,236 GHz, and a τf value ∼ −2.03 ppm/°C. This indicates the potential of the material for microwave communication applications. Finally, a dielectric filter with a center frequency of 11.55 GHz was successfully designed and fabricated using a Mg0.95Ca0.05TiO3‐MgO sample co‐doped with 0.5 wt% V2O5 and 0.75 wt% CeO2.The filter exhibited excellent performance with a bandwidth of less than 1.5 is about 40 MHz, the loss at the center frequency point was 0.7 dB, and the 3‐dB bandwidth exceeded 200 MHz, which holds a significant practical value.

Probing the influence of V2O5 and SBZKN composite additives on the magnetic characteristics and power loss of low-temperature sintered NiCuZn ferrites

Soft magnetic ferrites with exceptional magnetic characteristics and low power loss are in continuous demand in both academia and industry. In this work, a series of Ni0.22Cu0.31Zn0.47Fe1.98O4 ferrites doped with 0.5 wt% V2O5 and different SiO2-B2O3-ZnO-K2CO3-Na2CO3 (SBZKN) contents were synthesized using a conventional solid-phase method under a low sintering temperature of 925 ℃. The crystal phase, density, microstructure, grain size distribution, magnetic characteristics and power loss of the NiCuZn ferrites were studies to elucidate the composition-structure-property relationship. The underlying mechanisms were also thoroughly analyzed. The results showed that all the samples had a single-crystalline phase and dense microstructure when sintered at 925 ℃. As the SBZKN content increased, the density, saturation magnetization (Ms), residual magnetization (Br), complex permeability and quality factor (Q factor) exhibited a varying trend that increased initially and then decreased, while the coercivity (Hc) and power loss (Pcv) showed the opposite trend. The highest values of density, Ms, Br, magnetic permeability and Q factor of NiCuZn ferrites, obtained at an SBZKN content of 0.3 wt%, were 5.121 g/cm3, 51.07 emu/g, 188.47 mT, 389.8 and 114.3, respectively, while the lowest Hc and Pcv were obtained. The analysis showed that these outstanding magnetic and power loss characteristics were attributed to the uniform distribution of grain size and densification of NiCuZn facilitated by V2O5 and SBZKN incorporation.

An investigation on hot corrosion behavior of Al0.4MnCrCoFeNi high entropy alloy in different molten salts at 750 °C

The hot corrosion behavior of Al0.4MnCrCoFeNi high entropy alloy in different molten salts at 750 °C was investigated. The high entropy alloy was synthesized by vacuum melting and casting. The hot corrosion tests were performed in 75%Na2SO4 + 25%NaCl, 75%Na2SO4 + 20%NaCl + 5%V2O5, 75%Na2SO4 + 5%NaCl + 10%V2O5, and 60%Na2SO4 + 40%V2O5 mixture salts. Microstructural characterizations were carried out using a field emission scanning electron microscope equipped with an X-ray energy dispersive (EDS) analyzer. X-ray diffraction method with CuKα radiation was also used for phase analysis of corrosion products. The results indicated that Al0.4MnCrCoFeNi alloy had relatively good resistance to hot corrosion in 75%Na2SO4 + 25%NaCl molten salt compared to the other salts due to the formation of a protective layer consisting of Mn, Cr, and Al oxides. The addition of V2O5 to the mixture salt promoted the dissolution of the oxide layer in the molten salt and hence decreased the resistance of the alloy to hot corrosion. The mechanisms of hot corrosion were oxidation-sulfidation and fluxing. The least resistance to hot corrosion was observed in 60%Na2SO4 + 40%V2O5 mixture salt because the oxide scale was destroyed seriously, resulting in accelerated propagation of hot corrosion.

Structural investigation and effect of gamma-ray irradiation on barium borate glasses containing vanadium oxide

This work investigates the structural changes induced in barium borate glasses by gamma irradiation doses and vanadium doping using FTIR spectroscopic technique. Binary Barium borate parent glass and samples of the same composition containing different concentrations of vanadium oxide with formula xV2O5-(65-x)B2O3-35BaO (x = 0, 2, 4, 6, 8, and 10) were synthesized by melt quenching technique. FTIR spectroscopy approves the formation of both BO3 trigonal and BO4 tetrahedral structural units within the network backbone. V2O5 additions lead to borate network depolymerization by breaking B-O-B bonds and increasing V2O5 content causes systematic reductions in boroxol rings and B-O-B linkages, indicating disruption of the borate network. Gamma irradiation also damages the borate structure by cleaving B-O-B bonds in boroxol rings and BO3 units. This progressively converts BO3 to BO4 groups. Infrared spectroscopy reveals decreases in BO3 vibrations at higher doses as the network degrades. The radiation-induced network damage leads to changes in glass properties including thermal stability and hardness. A clearer understanding of borate structural modifications helps target these glasses for optical devices with controlled properties.

Enhancement of electrical and radiation shielding properties of vanadium doped lithium telluro-borate (LTB) glasses

Vanadium doped lithium telluro-borate (LTB) glasses of the composition (20-x)Li2O-20TeO2-60B2O3-(x)V2O5 (x = 0, 0.5, 1, 1.5 and 2 in mol %) were synthesised by melt quenching technique. The structural, optical, physical, electrical and radiation shielding parameters of the prepared glasses were investigated to determine the effect of vanadium in the LTB glass matrix. Density of LTB glasses were found to increases from 2.52 to 2.98 g/cm3 under addition of vanadium oxide and certain density derived structural parameters were studied. XRD pattern confirms the amorphous nature of the pristine and doped LTB glass. FTIR spectra shows the presence of various bonds in the vanadium doped LTB glasses. The direct optical bandgap (Eg) decreases due to the addition of V2O5 and leads to creation of defects in the LTB glasses thereby increasing the Urbach energy (Eu). Physical parameters like refractive index (n), molar refractivity (Rm), reflection loss (Lr), molar electronic polarizability (αm), transmission coefficient (T) and metallization criteria (M) were calculated. The electrical properties including dielectric constant (εʹ), conductivity (σ) and activation energies (Ea) were analysed and observed that Ea decreases under the addition of vanadium to the glass network proving the enhancement in electrical conductivity. Radiation shielding parameters such as MAC, LAC, HVL, TVL, MFP, R, ACS, ECS, Neff, Zeff, and Ceff were calculated using Phy-X/PSD and LTB_2V with the highest V2O5 additive shows enhanced result in gamma radiation shielding.

Vanadium Pentoxide Nanoparticles Doped ZnO: Physicochemical, Optical, Dielectric, and Photocatalytic Properties

In this work, vanadium pentoxide nanoparticles (V2O5) derived by the chemical coprecipitation route were used to synthesize various vanadium-doped ZnO nanocomposite samples via the standard solid-state reaction process. The effect of V2O5 nanoparticles on the physicochemical properties of ZnO was discussed. The prepared samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy combined with energy-dispersive spectroscopy, and UV-visible spectroscopy. A diffuse reflectance spectroscopic approach is described to determine the bandgap energy (Eg) of the samples. The dielectric and photocatalytic characteristics are also examined. The photocatalytic performance of the prepared materials was tested under visible light using methylene blue (MB) as a pollutant dye model. As a result, it is found that the addition of V2O5 enhances the photodegradation of MB. The kinetics of the photodegradation reaction was found to follow a pseudo-first-order model.

The effect of different transition metal oxides on the characterization and photoluminescence properties of borosilicate glass ceramics containing nanosized anatase type-TiO2

In this study, crystallization of anatase type-TiO2 was achieved in the traditional borosilicate glasses (Na2O.B2O3.SiO2) for the first time. The effect of the TiO2 /Na2O ratio was studied to optimize the selected glass composition, also the effect of adding a definite amount of different transition metal oxides (TMO) was studied. The glasses were prepared via the conventional melt-quenching method. According to DSC results, heat treatment at 650 °C /10hrs was applied to convert the glasses into glass ceramics. XRD detected the crystallization of anatase, rutile, and cristobalite. A sample with a lower value of TiO2 /Na2O revealed a higher degree of crystallization of anatase than that with a higher value. Both Cr2O3 and NiO additions enhanced the crystallization of cristobalite; while additions of CoO, Fe2O3, V2O5, MnO, CuO or ZnO significantly enhanced the crystallization of anatase in the same order. The morphology of glass ceramic was observed by TEM and SEM, which revealed crystal size < 50 nm. The optical band gap was estimated from UV-Visible absorption spectra, it depicted a wide range of values (4.4–2.1 eV). PL spectra revealed emission colors varied from purple to blue color according to TMO and TiO2 /Na2O ratio. The obtained materials can be utilized as electron transport layers for perovskite solar cells.

Effects of mesoporous TiO2 with addition of V2O5 and rinsing with various solvents on the properties of dye-sensitized solar cells

Dye-sensitized solar cells (DSSC) have received much attention since they are simple, easily manufactured, inexpensive, and offer reasonable conversion efficiency. Mesoporous TiO2 with the addition of V2O5 nano-particles (0, 0.5, 1.0, 1.5 and 2.0 wt%) as a photoanode in DSSC have been successfully fabricated using a spin-coating method. Titanium tetrachloride (TiCl4) was used to synthesize a thin TiO2 blocking layer to enhance the performance of TiO2 photoanode in DSSC. After annealing treatment at 450 °C, the TiO2 blocking layer showed an amorphous structure. Performance was examined after soaking N719 dye and rinsing with five different solvents (ethanol, isopropanol, acetone, methanol, and diethyl ether). The results show that removing unanchored dye molecules using acetone solution can increase the specific surface area and dye adsorption amount of TiO2, resulting in good Jsc and photovoltaic efficiency. A conversion efficiency of 8.5% was achieved using fluorine doped tin oxide glass, a thin blocking layer, mixing 0.5 wt% V2O5 with mesoporous TiO2 and rinsing with an acetone solution.

Deciphering the structural origins of high sulfur solubility in vanadium-containing borosilicate glasses

The addition of V2O5 has been long known to increase the sulfur (as SO42-) solubility in borosilicate glasses. However, the mechanism governing this effect is still unknown. Although several studies have been published in the past two decades attempting to decipher the structural origins of increasing sulfur solubility as a function of V2O5 in borosilicate glasses, most of these studies remain inconclusive. The work presented in this paper attempts to answer the question, “Why does V2O5 increase sulfur solubility in borosilicate glasses?” Accordingly, a series of melt-quenched glasses in the system [30 Na2O – 5 Al2O3 – 15 B2O3 –50 SiO2](100-x) – xV2O5, where x varies between 0 – 9 mol.%, have been characterized for their short-to-intermediate range structure and the redox chemistry of vanadium using 11B, 27Al, 51V MAS NMR, Raman, and XPS spectroscopy. The impact of V2O5 on sulfur solubility in glasses has been followed by ICP-OES. The addition of ≤ 5 mol.% V2O5 results in a linear increase in sulfur solubility in the investigated glass system. Based on the results, we hypothesize that adding vanadium to the glasses increases their network connectivity, but reduces the network rigidity by replacing stronger Si–O–Si linkages with weaker Si–O–V linkages and forming (VO3)n-single chains. These modifications to the glass structure increase the flexibility of the network, thus making it possible to accommodate SO42− in their voids/open spaces.

The structure, optical basicity, ligand field strength and shielding parameters of alkali/alkaline borate glasses doped with V2O5

In this work, we study the structural, optical and radiation shielding properties of Na2O–CaO-borate glass doped with different amounts of V2O5. A glass system with the composition (10.5CaO+ 16.5Na2O+ (73-x)B2O3+ xV2O5; where x = 0, 2.5, 5 and 10.5 mol%) was produced following the melt quenching technique. The molar volume and density of glasses both increase with the increase in V2O5:B2O3 ratios. Moreover, the average ligand field strength reduced from 2.32 to 2.15 × 1016 cm2 with the increase in V2O5:B2O3 ratios, which correlates with the increased values of molar volume and interatomic separations. Furthermore, the optical basicity of the glass samples increased from 0.601 to 0.666 with increasing V2O5:B2O3 ratios. The optical absorption spectra are studied for further investigation of the optical features. To extract the absorption edge and the absorption bands, a deconvolution process was applied to the absorption spectra. The obtained bands from this deconvolution process confirmed the presence of vanadium in its oxidation states V3+, V4+ and V5+. Furthermore, more additions of V2O5 produced an obvious reduction in Eg values from 3.69 to 3.08 eV along with a redshift in the fundamental absorption edges. These results were attributed to the further creation of nonbridging oxygens within the glass matrix. Furthermore, the addition of V2O5 rather than B2O3 enhances the radiation shielding parameters. Accordingly, the CaNaBV10.5 glass sample is the best attenuator among the fabricated CaO–Na2O–B2O3–V2O5 glasses due to the highest mass attenuation coefficient and lowest half-value layer. Moreover, the half-value layer values of the present glasses were compared to some common materials in the radiation shielding field. From this comparison, we concluded that all glass samples are better than commercial glass windows and ordinary concrete.

Effect of V2O5 on Consolidation, Reduction, and Softening-Melting Behavior of High-Cr Vanadium Titanomagnetite

Vanadium titanomagnetite is an important mineral resource. It is a raw material for ironmaking, vanadium extraction, strategic metal titanium production, and titanium dioxide production. In this study, high chromium vanadium titanomagnetite (High-Cr VTM) and ordinary iron ore were used as raw materials for pelletizing. The effect of V2O5 on the preparation and properties of High-Cr VTM pellets was studied. The influence of V2O5 on the properties of the green pellets, the compressive strength of oxidized pellets, the reduction swelling index and reduction degree, softening-melting behavior, and the migration law of Fe, Ti, and Cr in the reduction process were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that with the increase in V2O5 content, the properties of the green pellets basically showed a trend of first decreasing and then increasing but all met the basic requirements of pelletizing. When the added amount of V2O5 in the pellet was 6%, the compressive strength of the oxidized pellet was the lowest at only 2565 N/pellet but it still met the quality requirements for pellets in blast furnace production. As the dosage of V2O5 increased, the reduction swelling index and reduction degree of the pellets showed a trend of first increasing and then decreasing. The addition of V2O5 can increase the softening initial temperature, softening final temperature, melting start temperature, and dripping temperature of the High-Cr VTM pellets, narrowing the softening interval, and expanding the melting dripping interval. The experimental results provided a data reference for revealing the influence of V2O5 on High-Cr VTM pellets during the blast furnace smelting process.

Effects of Dopants and Processing Parameters on the Properties of ZnO-V2O5-Based Varistors Prepared by Powder Metallurgy: A Review.

This article reviews the progress in developing ZnO-V2O5-based metal oxide varistors (MOVs) using powder metallurgy (PM) techniques. The aim is to create new, advanced ceramic materials for MOVs with comparable or superior functional properties to ZnO-Bi2O3 varistors using fewer dopants. The survey emphasizes the importance of a homogeneous microstructure and desirable varistor properties, such as high nonlinearity (α), low leakage current density (JL), high energy absorption capability, reduced power loss, and stability for reliable MOVs. This study investigates the effect of V2O5 and MO additives on the microstructure, electrical and dielectric properties, and aging behavior of ZnO-based varistors. The findings show that MOVs with 0.25-2 mol.% V2O5 and MO additives sintered in air over 800 °C contain a primary phase of ZnO with a hexagonal wurtzite structure and several secondary phases that impact the MOV performance. The MO additives, such as Bi2O3, In2O3, Sb2O3, transition element oxides, and rare earth oxides, act as ZnO grain growth inhibitors and enhance the density, microstructure homogeneity, and nonlinearity. Refinement of the microstructure of MOVs and consolidation under appropriate PM conditions improve their electrical properties (JL ≤ 0.2 mA/cm2, α of 22-153) and stability. The review recommends further developing and investigating large-sized MOVs from the ZnO-V2O5 systems using these techniques.

Development of antibacterial and morphological features of scaffolds based on polycaprolactone encapsulated with copper oxide/vanadium oxide for wound dressing applications

The development of highly effective dressing materials for human injuries that meet the complex requirements for clinical examination is still a challenge. In this regard, different biomaterials could be examined for wound dressing targets. Among these materials, polycaprolactone (PCL) is high biocompatible polymeric substance and has been used for numerous pharmaceutical applications. Furthermore, targeting antibacterial behavior could be done by merging additional nanoparticles such as copper oxide (CuO) and vanadium Oxide (V2O5). The scaffolds could be fabricated using the cast method, which is one of the most simple and facile methods. The morphological features and the surface roughness of the fabricated could be examined using X-ray diffraction, Raman spectroscopy, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) tests. The contact angle plays a significant role in studying the wettability of the scaffolds and the hydrophilic or hydrophobic behavior of the composed films. Besides the antibacterial behavior to evaluate the effectiveness of these scaffolds to protect the injury until the healing. The cell viability against human normal cells to examine the biocompatibility of the proposed compositions. In this regard, the topographical images show a smooth surface with random pores that have diameters in the range of 0.5–1.5 μm for pure PCL while, the porosity decreased with the addition of ginger and V2O5. The blend of CuO/V2O5/ginger@ PCL represents a noticeable increase in porosity with a diameter between 0.5 and 3 μm. The contact angles were recorded respectively at 55.02°, 54.12°, 53.89°, and 53.71° which refer to the tendency of the scaffolds to the hydrophilic behavior. In addition, the anti-bacterial activity of CuO/V2O5/ginger@PCL was represented with the diameter of the inhibition zone equal to 17.6±1.2 mm for E. coli and 12.3±1.2 mm for S. aureus.

Addition of V2O5 in lithium aluminium oxy-fluorophosphate glass system: A possible glassy cathode?

Glass formation region in ternary LiF‒Al(PO3)3‒V2O5 system was determined by melt quenching technique. Homogeneous glasses were obtained by varying V2O5 between 2‒70 mol%. 80LiF‒20Al(PO3)3 composition was chosen as parent glass. V2O5 was added until stable glasses could be cast. V2O5 was substituted for LiF and/or Al(PO3)3 to test its role as glass modifier and/or glass former in presence of Al(PO3)3. Glasses were characterized using XRD, DSC, ICP-AES, FTIR and Electrical Impedance Spectroscopy. V2O5 played dual role‒ of network modifier at low concentrations and of network former with its progressive additions, changing glass structure from predominantly phosphate to vanadophosphate network. These structural changes correlated with the measured properties. Electrical conductivity increased substantially upon V2O5 addition and changed from being predominantly ionic to mixed conduction, with comparable ionic and electronic contributions for ≥ 35 mol% of V2O5, making it a possible candidate for glassy cathode.

Microstructure and gyromagnetic properties of low-sintered LiZnTi ferrite doped with nano-LiZn and V2O5 additives

In this study, nanoparticles of LiZn ferrite (nano-LiZn, 0.0–10.0 wt. %) fabricated via the sol-gel method and V2O5 particles were added into a Li0.43Zn0.27Ti0.13Fe2.17O4 (LiZnTi) ferrite to realize low temperature sintering. The effects of the nano-LiZn ferrite addition on the crystalline phase formation, microstructure, and magnetic properties of LiZnTi ferrite were systematically investigated. X-ray diffraction results reveal that the LiZnTi ferrite doped with nano-LiZn and V2O5 additives present a pure spinel structure, which can be explained by liquid phase of V2O5 and spinel structure of nano-LiZn, as revealed by high-resolution transmission electron microscopy and selected area electron diffraction data. Scanning electron microscopy images show that the addition of nano-LiZn leads to a change in the microstructure, with the grains becoming uniform and dense. Additionally, the variation in the saturation magnetization (Ms) depends on the LiZn content. In particular, Ms increases with increasing LiZn content from 2.0 to 10.0 wt. %. Finally, the LiZnTi ferrite doped 4.0 wt. % nano-LiZn and 0.60 wt. % V2O5 possesses a narrow ferromagnetic resonance linewidth of 197 Oe, a reduced coercivity of 192.6 A/m, and an improved bulk density of 4.73 g/cm3.

In Vitro Studies Demonstrate Antitumor Activity of Vanadium Ions from a CaO-P2O5-CaF2:V2O5 Glass System in Human Cancer Cell Lines A375, A2780, and Caco-2.

In this research, we investigated the structural and biological properties of phosphate glasses (PGs) after the addition of V2O5. A xV2O5∙(100 − x)[CaF2∙3P2O5∙CaO] glass system with 0 ≤ x ≤ 16 mol% was synthesized via a conventional melt-quenching technique. Several analysis techniques (dissolution tests, pH, SEM-EDS, FT-IR, and EPR) were used to obtain new experimental data regarding the structural behavior of the system. In vitro tests were conducted to assess the antitumor character of V2O5-doped glass (x = 16 mol%) compared to the matrix (x = 0 mol%) and control (CTRL-) using several tumoral cell lines (A375, A2780, and Caco-2). The characterization of PGs showed an overall dissolution rate of over 90% for all vitreous samples (M and V1−V7) and the high reactivity of this system. EPR revealed a well-resolved hyperfine structure (hfs) typical of vanadyl ions in a C4v symmetry. FT-IR spectra showed the presence of all structural units expected for P2O5, as well as very clear depolymerization of the vitreous network induced by V2O5. The MTT assay indicated that the viability of tumor cells treated with V7-glass extract was reduced to 50% when the highest concentration was used (10 µg/mL) compared to the matrix treatment (which showed no cytotoxic effect at any concentration). Moreover, the matrix treatment (without V2O5) provided an optimal environment for tumor cell attachment and proliferation. In conclusion, the two types of treatment investigated herein were proven to be very different from a statistical point of view (p < 0.01), and the in vitro studies clearly underline the cytotoxic potential of vanadium ions from phosphate glass (V7) as an antitumor agent.

Structural and optical properties of vanadium doped lithium barium borate glasses

This article reports the optical and structural characteristics of (1-x)[50B2O3-30Li2O-20BaO]-xV2O5 glasses, where x has the values as 0, 0.2, 0.4, 0.6, 0.8, 1.0 mol% respectively. Popular technique for glass preparation, melt-quenching has been employed for glass batch preparation. X-ray diffractometric studies provided the confirmation for the amorphous nature of prepared glass samples. Fourier Transform Infra-Red (FTIR) spectroscopy of these glasses show absorption peaks at 574 cm−1, 710 cm−1, 934 cm−1, 1226 cm−1, 1385 cm-1and 2924 cm−1. The peak at 710 cm−1 is arising from B-O-B vibrations. The vibrations in [BO4] groups are responsible for the absorption peak at 900–1000 cm−1. The peaks observed between 1100 and 1400 cm−1 are due to the strong vibrations of B-O-B from [BO3] triangles. UV–Vis NIR spectroscopy of the prepared glass samples was reported and the physical parameters of the glasses have been calculated from the data. The densities of these glass samples were evaluated by using the Archimedes principle, and it was discovered that the density decreased on the successful addition of V2O5 from 3.094 to 3.024 g/cm3. The molar volume was calculated and has been observed that it increased with the addition of V2O5 as 24.059–24.9745. The indirect and direct band gap energies of the glass samples were evaluated byusing UV–Vis NIR spectroscopy, and they were found to be decreased from 4.114 − 3.511 eV and 3.25–2.75 eV respectively. It has been also evaluated how the refractive index varies with thewavelength. The results are discussed concerning the structural refinement in these borate glasses.

Nanosize Al2O3 reinforcement in Si-rich aluminum MMC for enhanced tribological performance in engine components

Aluminum metal matrix composites are increasingly popular nowadays because of their wide range of uses. The low weight and excellent mechanical qualities, such as strength and hardness, of Al-Al2O3 composites make them useful in many fields, including automotive, aerospace, electronics, aeronautics, and military. Most of the engine components are made of aluminum-silicon alloys because of their excellent casting and forming properties. In engine components wear is a crucial parameter to be considered therefore in this investigation Al-Si alloy with varying percentages of V2O5 has been considered to develop the Al-Al2O3 composite and evaluate its tribological aspect. For composite development, a novel in-situ approach has been used with the help of the stir-casting method. The tribological behavior of the different composites was examined experimentally and studied with sliding distance, applied load, and the amount of reinforcement. Composites show a significant increase in hardness relative to the base alloy because of the generation of hard alumina particles within the melt. The wear behavior of in-situ Al-Al2O3 composites was studied using a pin-on-disc setup. In terms of COF and wear rate, the composite with a 1% addition of V2O5 performed better in the trial.

Mixed Ionic and Electronic Conduction in TeO2-ZnO-V2O5 Glasses towards Good Dielectric Features.

The melt-quenching technique was used to synthesize tellurite glasses of the chemical composition 80TeO2-(20-x) ZnO-xV2O5. X-ray diffraction (XRD) patterns indicate the amorphous nature of the prepared glasses. Raman and FTIR measurements demonstrate a progressive substitution of the Te-O-Te linkages by the Te-O-V bridges and the formation of VO4 and VO5 units by a change of the vanadium coordination due to the higher number of oxygens incorporated by further addition of V2O5. The AC conductivity was investigated in the frequency range of 40 Hz to 107 Hz between 473 K to 573 K. A good coherence of the AC conductivity was found using a model correlating the barrier hopping (CPH) and the dominant conduction process changes from ionic to polaronic with the addition of V2O5. The dielectric constant exhibits high values in the range of lower and medium frequencies. Both variations of the electric modulus and the dielectric loss parameters with frequency and temperature showed a relaxation character mainly assigned to the vanadate phases. The electric modulus displays a non-Debye dielectric dispersion and a relaxation process. The present results open the door to future zinc-tellurite glasses-doped vanadium exploitation as a potential electrolyte-based material for solid-state batteries.