Pure Composition Research Articles

Influence of tungsten oxide concentration on structural, morphological, compositional, linear and non-linear optical properties, and vibrational properties on NiO:WO3 thin films

Mixed nickel-tungsten oxide, NiO:WO3 (90:10, 85:15) thin films with different tungsten oxide (WO3) concentrations of 10 and 15% were deposited using the radio frequency (RF) sputtering technique. An X-ray diffraction analysis reported the amorphous nature of the films. A SEM study showed smooth morphology. EDAX confirms the compositional purity, in which the nickel content decreases, while the tungsten and oxygen content increase with an increased WO3 concentration. The average transmittance of the NiO:WO3 (90:10, 85:15) films decreases from 79 to 75% as a consequence of increased thickness. The Urbach energy (Eu) enhances because of increased defects (localized states) inside the films induced by tungsten oxide addition. The energy bandgap decreases from 2.66 to 2.48 eV due to the formation of new localized energy states inside the band gap (Eg). The refractive index (n) acquired from different proposed models for the entire UV–Vis–NIR region has increased with increasing WO3 concentration, implying the escalation in densification (or packing density) of prepared films. The optical parameters like n, k, ε1, ε2, electronic polarizability (αp), optical conductivity (σop), electric conductivity (σe), volume and the surface energy loss function (VELF AND SELF) vary with WO3 concentration. The dispersion energy parameters (Eo, Ed), resulting from the Wemple and Didomenico (WD) model, decreases. The optical non-linear susceptibility, χ(3), decreased with increasing WO3 concentration. The photoluminescence (PL) emissions were perceived at 368 nm and 423 nm, assignable to 3 d8 Ni2+ ions transitions. Micro-Raman detected peaks at 570 cm−1 and 1100 cm−1 ascribing Ni–O bond vibrations, whereas the peak spotted at 870 cm−1 is ascribed to a W–O bond vibration. The deposited films are good enough for electrochromic and optoelectronic device fabrications.

Highly Tunable MOCVD Process of Vanadium Dioxide Thin Films: Relationship between Structural/Morphological Features and Electrodynamic Properties.

The monoclinic structures of vanadium dioxide are widely studied as appealing systems due to a plethora of functional properties in several technological fields. In particular, the possibility to obtain the VO2 material in the form of thin film with a high control of structure and morphology represents a key issue for their use in THz devices and sensors. Herein, a fine control of the crystal habit has been addressed through an in-depth study of the metal organic chemical vapor deposition (MOCVD) synthetic approach. The focus is devoted to the key operative parameters such as deposition temperature inside the reactor in order to stabilize the P21/c or the C2/m monoclinic VO2 structures. Furthermore, the compositional purity, the morphology and the thickness of the VO2 films have been assessed through energy dispersive X-ray (EDX) analyses and field-emission scanning electron microscopy (FE-SEM), respectively. THz time domain spectroscopy is used to validate at very high frequency the functional properties of the as-prepared VO2 films.

Synthesis, characterization, and antiparasitic effects of zinc oxide nanoparticles-eugenol nanosuspension against Toxoplasma gondii infection

BackgroundIn this study, zinc oxide nanoparticles-coated with eugenol (ZnO@Eug) were synthesized and evaluated as a nanosuspension (NSus) formulation against Toxoplasma gondii in vitro and in vivo. MethodsAn anti-Toxoplasma activity assay for ZnO@Eug NSus was conducted in vitro, ex vivo, and in vivo. FTIR spectroscopy confirmed the formation of ZnO@Eug NSus by detecting several functional groups involved; EDX and SEM demonstrated the grain of ZnO-NPs embedded with Eug and compositional purity. ResultsSurface charge (ZP) and size distribution (DLS) of ZnO@Eug NSus were determined to be −22.7 mV and 109.6 nm, respectively. According to the release kinetics, approximately 60% of the ZnO-NPs and Eug were released in the first 45 min. In the cytotoxicity assay, ZnO-NPs, Eug, and ZnO@Eug NSus had IC50 values of 71.85, 22.39, and 2.02 mg/mL, respectively. The therapeutic efficacy of ZnO@Eug against T. gondii was 56.3%, which was not significantly different from that of spiramycin (58.9%) (Positive-control). The tissue tachyzoites in the liver, spleen, and peritoneum were less than 50% in groups treated with Eug, spiramycin, and ZnO@Eug NSus compared to the control. ZnO@Eug-treated groups showed a survival rate of up to 13 days. ConclusionsThe ZnO@Eug NSus demonstrated antiparasitic activity against T. gondii with minimal toxic effects and high efficiency in increasing the survival of infected mice. The nanoformulations of ZnO-NPs incorporated with Eug could, in the future, be considered for treating toxoplasmosis in humans and animals if a detailed study was conducted to determine the precise dose and measure side effects.

Preparation of NASICON Silico Phosphates of Composition Na1 + xZr2SixP3 – xO12 by Pyrolysis of Solution in Melt

A new method for preparing Na1 + xZr2SixP3 – xO12 (0 x 3) based on pyrolysis of solution containing a mixture of organic components in rosin melt has been proposed. Effect of superstoichiometric amounts of sodium and phosphorus on the phase composition of synthesis products has been proved. It has been found that precursor for the sample of maximal purity of phase composition is prepared at molar ratio Na : Zr : Si : P = (1.15 + x) : 2 : x : (y – x), where y = 3 (1.20 + x)/(1 + x). Precursor calcination temperature is 1000°C. Different NASICON compositions without crystalline admixtures have been obtained in the range 1.5 ≤ x ≤ 2.12. The prepared samples have been studied by X-ray powder diffraction and scanning electron microscopy. The disclosed method of synthesis is promising for the preparation of NASICON as both bulk materials and thin layer coatings.

High nitrogen and argon diffusion in cyclic olefin copolymer foil versus temperature

Measurements of nitrogen and argon diffusion coefficient in cyclic olefin copolymer (COC) have been performed at different temperatures ranging between 21 °C and 101 °C. Optical transparent COC foils have been prepared with 10 μm thickness and total surface of about 25 cm2. The foils have exhibited high purity in composition. The morphology of the COC surface has been investigated by Scanning Electron and Atomic Force Microscopies. The room temperature measured diffusion coefficients, of about 6.56 × 10−3 cm2/s and 6.30 × 10−3 cm2/s for N2 and Ar, respectively, have been obtained with a home-made experimental set-up by measuring the gas pressure gradient reduction applied to the two faces of COC thin foils versus the time. The foils show a significant increase of the N2 and Ar diffusion coefficients with the temperature. The native amorphous nature, the obtained nano-porous structure, the damage suffered by the thin foils of COC under high applied pressure are responsible of the evaluated high diffusion coefficients for nitrogen and argon gases. The experimental apparatus to measure the diffusion coefficients vs. temperature, the obtained results, the COC sheets microstructure, the measurements comparison with the literature data and possible COC applications in biomedicine are presented and discussed.

Enhanced photocatalytic activity of Cu and Ni-doped ZnO nanostructures: A comparative study of methyl orange dye degradation in aqueous solution

Heterogeneous photocatalysis has been considered one of the most effective and efficient techniques to remove organic contaminants from wastewater. The present work was designed to examine the photocatalytic performance of metal (Cu and Ni) doped ZnO nanocomposites in methyl orange (MO) dye degradation under UV light illumination. The wurtzite hexagonal structure was observed for both undoped/doped ZnO and a crystalline size ranging between 8.84 ± 0.71 to 12.91 ± 0.84 nm by X-ray diffraction (XRD) analysis. The scanning electron microscope (SEM) and energy dispersive X-ray (EDX) revealed the irregular spherical shape with particle diameter (34.43 ± 6.03 to 26.43 ± 4.14 nm) and ensured the purity of the individual elemental composition respectively. The chemical bonds (O–H group) and binding energy (1021.8 eV) were identified by Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) results respectively. The bandgap energy was decreased from 3.44 to 3.16 eV when Ni dopant was added to the ZnO lattice. The comparative photocatalytic activity was observed in undoped and doped nanocomposites and found to be 76.31%, 81.95%, 89.30%, and 83.39% for ZnO, Cu/ZnO, Ni/ZnO, and Cu/Ni/ZnO photocatalysts, respectively, for a particular dose (0.210 g) and dye concentration (10 mg L−1) after 180 min illumination of UV light. The photocatalytic performance was increased up to 94.40% with the increase of pH (12.0) whereas reduced (35.12%) with an increase in initial dye concentration (40 mg L−1) using Ni/ZnO nanocomposite. The Ni/ZnO nanocomposite showed excellent reusability and was found 81% after four consecutive cycles. The best-fitted reaction kinetics was followed by pseudo-first-order and found reaction rate constant (0.0117 min−1) using Ni/ZnO nanocomposite. The enhanced photodegradation efficiency was observed due to decreases in bandgap energy and the crystalline size of the photocatalyst. Therefore, Ni/ZnO nanocomposite could be used as an emerging photocatalyst to degrade bio-persistent organic dye compounds from textile wastewater.

Geochemistry and Sr, S, and O stable isotopes of Miocene Abu Dhabi evaporites, United Arab Emirates

This study investigates for the first time the subsurface Miocene evaporite facies (Gachsaran Formation) in Abu Dhabi, United Arab Emirates. Forty-five evaporite rock samples were selected for petrographic, mineralogical, and geochemical investigations and stable isotope analyses to decipher their origin and constrain their age. Secondary gypsum with anhydrite relics dominates the investigated evaporitic rocks, with minor amounts of clays, dolomicrite, Fe/Ti oxides, and celestite. These samples are characterized by their excellent purity and low variability in geochemical composition. The distribution of trace element concentrations is significantly influenced by continental detrital intake. The main focus of the study is to determine the strontium, sulfur, and oxygen stable isotope compositions. The measured 87Sr/86Sr values of 0.708411–0.708739 are consistent with Miocene marine sulfates and indicate ∼21.12–15.91 Ma (Late Aquitanian-Burdigalian). The δ34S and δ18O values are 17.10‰–21.59‰ and 11.89‰–19.16‰, respectively. These values are comparable to those of Tertiary marine evaporites. The relatively low values of δ34S suggest that non-marine water possesses little influence on S distribution. The geochemical composition and Sr, S, and O isotope distributions of the Abu Dhabi gypsum facies from the Gachsaran Formation reveals that their source brines were marine (coastal saline/sabkha) with subordinate continental input.

Design and development of four-layer anti-reflection coating stacks (ZnS and YF3 thin films) for HgCdTe-based mid-wave infrared detectors

The four-layer anti-reflection coating (ARC) film stacks (consisting of four layers of zinc sulphide (ZnS) and yttrium fluoride (YF3) materials with an optimized thickness of 699 ± 2.6 nm) were grown on the backside of the HgCdTe (mercury cadmium telluride)-CdZnTe (cadmium zinc telluride) assembly (i.e., CdZnTe substrate) using the thermal-evaporation deposition technique. Successively, the characterization tools like atomic force microscope, X-ray diffractometer, energy dispersive X-ray spectrometer, and scanning electron microscope were utilized to realize the optimized ARC film stacks. ARC stacks (ZnS/YF3/ZnS/YF3) with cubic zinc blende phase and preferred orientation (111) were confirmed. The desired surface morphology (dense and low roughness), elemental composition (purity), and micro-structural features (reasonable grain size and material continuity) of ARC films were achieved. The optimized films were further examined through their utilization in the fabrication of two similar ARC stacks/structures with a configuration of YF3/ZnS/YF3/ZnS/CdZnTe–HgCdTe and Fourier Transform infrared spectrometer was used to measure their reflectance. ARC film stacks (with remarkably thin film thickness and good repeatability) have reduced the reflection of HgCdTe–CdZnTe assembly to a minimum value from 22% to < 1.0% within the mid-wave infrared spectral region, which further validates theoretically. Thus, the four-layer ARC film stacks are the effective reflection agent that could be used to fabricate high-performance HgCdTe infrared detectors.

Pectin/PVA and pectin-MgO/PVA films: Preparation, characterization and biodegradation studies

There is a great demand to replace non-renewable materials with eco-friendly renewable materials for many applications in recent times. In the present study, such an attempt was made to substitute synthetic polymer-based films used for food packaging applications with films prepared out of renewable materials derived from waste. The pectin/polyvinyl alcohol (PP) and pectin-MgO/polyvinyl alcohol (PMP) films were prepared and characterized to ascertain their suitability for packaging applications. To improve the mechanical strength and thermal stability of films, MgO nanoparticles were incorporated in situ into the polymer matrix. The pectin used in the study was extracted from citrus fruit peel. The prepared nanocomposite films were evaluated for physico-mechanical properties, water contact angle, thermal stability, crystallinity, morphology, compositional purity and biodegradability. The elongation at break for PP film was 42.24% and for PMP film it was 39.18%. Also, the ultimate modulus in terms of MPa for PP film was 6.8 and for PMP it was 7.9. So, it was found that PMP films have better ductility and modulus than PP films due to the presence of MgO nanoparticles. The spectral studies confirmed the compositional purity of the prepared films. The biodegradation studies revealed that both films could be degraded at ambient conditions at appreciable time span, suggesting them to be a better choice as an environmentally friendly food packaging material.

A Double Perovskite BiFeMoO6: Microstructural, Optical, Dielectric and Transport Properties

In this communication, the synthesis (solid-state sintering) and characterization of a double perovskite BiFeMoO6 are reported. Analysis of X-ray diffraction (XRD) data provides monoclinic crystal symmetry with an average crystallite size of 85.6[Formula: see text]nm and lattice strain of 0.00078, respectively. The microstructural analysis of the sample was done using a scanning electron microscope (SEM) and the results show that grains are well-grown and distributed uniformly throughout the sample surface. The grains are visible clearly due to well-defined grain boundaries, and the effect on the mechanism of electrical ac conductivity was studied. The compositional purity of the sample was checked by energy dispersive X-ray (EDX) analysis spectrum which supports the presence of all constituent elements (Bi, Fe, Mo and O) in both weight and atomic percentages. The study of the Ultraviolet–Visible spectrum provides a bandgap energy of 1.8[Formula: see text]eV, suitable for photovoltaic applications. The measurements of the dielectric were used to confirm the existence of the Maxwell–Wagner type of dispersion. The study of impedance spectroscopy helps to understand the negative temperature coefficient of resistance (NTCR) character while the electrical modulus measurements claimed a non-Debye relaxation mechanism in the sample. The study of ac conductivity reveals the fact of thermally activated conduction mechanism in the sample. The presence of the semiconducting nature of the sample was checked from both Nyquist plots and Cole–Cole plots. The study of the resistance versus temperature reveals the fact of negative temperature coefficient (NTC) thermistor character and is suitable for some temperature sensor devices.

Thermally induced solid-state reaction of Fe2(SO4)3 with NaCl or KCl: a route to β-Fe2O3 synthesis

β-Fe2O3 is a rare crystalline polymorph of the ferric oxide family with an interesting application potential, e.g., in photocatalysis. In this study, the effect of different alkali salts addition, namely NaCl and KCl, on the preparation of β-Fe2O3 via thermally induced solid-state reaction was investigated. Two series of samples were prepared by calcining two different mixtures, Fe2(SO4)3 + NaCl (molar ratio 1:3) and Fe2(SO4)3 + KCl (molar ratio 1:3) at temperatures from 350 to 700 °C. Although the addition of either alkali salt led the preparation of β-Fe2O3 particles in wide temperature range up to 650 °C, differences in the overall phase composition and β-Fe2O3 purity were observed between the two series. The addition of KCl to Fe2(SO4)3 allowed the preparation of pure β-Fe2O3 (≥ 95%) in relatively wide temperature range of 450‒600 °C, while in the case of NaCl, pure β-Fe2O3 (≥ 95%) was found only in samples calcined at 500 °C and 550 °C. Other phases could be identified as additional ferric oxide polymorphs, γ-Fe2O3 and α-Fe2O3. The in situ XRD results suggest that, in the case of NaCl + Fe2(SO4)3 reaction, simultaneous formation of β-Fe2O3 and α-Fe2O3 may be possible between 350 and 500 °C, depending on the reaction conditions.

Proteomic Analysis, Immuno-Specificity and Neutralization Efficacy of Pakistani Viper Antivenom (PVAV), a Bivalent Anti-Viperid Antivenom Produced in Pakistan.

Snakebite envenoming is a neglected tropical disease prevalent in South Asia. In Pakistan, antivenoms are commonly imported from India despite the controversy over their effectiveness. To solve the problem, the locals have developed the Pakistani Viper Antivenom (PVAV), raised against Sochurek's Saw-scaled Viper (Echis carinatus sochureki) and Russell's Viper (Daboia russelii) of Pakistani origin. This study is set to evaluate the composition purity, immuno-specificity and neutralization efficacy of PVAV. Chromatographic and electrophoretic profiling coupled with proteomic mass spectrometry analysis showed PVAV containing high-purity immunoglobulin G with minimum impurities, notably the absence of serum albumin. PVAV is highly immuno-specific toward the venoms of the two vipers and Echis carinatus multisquamatus, which are indigenous to Pakistan. Its immunoreactivity, however, reduces toward the venoms of other Echis carinatus subspecies and D. russelii from South India as well as Sri Lanka. Meanwhile, its non-specific binding activities for the venoms of Hump-nosed Pit Vipers, Indian Cobras and kraits were extremely low. In the neutralization study, PVAV effectively mitigated the hemotoxic and lethal effects of the Pakistani viper venoms, tested in vitro and in vivo. Together, the findings suggest the potential utility of PVAV as a new domestic antivenom for the treatment of viperid envenoming in Pakistan.

Decomplexation proteomic analysis and purity assessment of a biologic for snakebite envenoming: Philippine Cobra Antivenom.

Philippine Cobra Antivenom (PCAV) is the only snake antivenom manufactured in the Philippines. It is used clinically to treat envenoming caused by the Philippine Spitting Cobra (Naja philippinensis). While PCAV is effective pharmacologically, it is crucial to ensure the safety profile of this biologic that is derived from animal plasma. This study examined the composition purity of PCAV through a decomplexation proteomic approach, applying size-exclusion chromatography (SEC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and tandem mass spectrometry liquid chromatography-tandem mass spectrometry (LC-MS/MS). SDS-PAGE and SEC showed that the major protein in PCAV (constituting ∼80% of total proteins) is approximately 110 kDa, consistent with the F(ab')2 molecule. This protein is reducible into two subunits suggestive of the light and heavy chains of immunoglobulin G. LC-MS/MS further identified the proteins as equine immunoglobulins, representing the key therapeutic ingredient of this biologic product. However, protein impurities, including fibrinogens, alpha-2-macroglobulins, albumin, transferrin, fibronectin and plasminogen, were detected at ∼20% of the total antivenom proteins, unveiling a concern for hypersensitivity reactions. Together, the findings show that PCAV contains a favorable content of F(ab')2 for neutralization, while the antibody purification process awaits improvement to minimize the presence of protein impurities.

A double perovskite BaCaZrMnO6: synthesis, microstructural dielectric, transport and optical properties

In this communication, synthesis (solid-state reaction) and characterization of a double perovskite BaCaZrMnO6 are reported. The Williamson–Hall method is used to compute average crystallite and micro-lattice strain in the prepared sample after structural analysis with X-Pert High-Score software. The sample's microstructural characteristics were investigated using a scanning electron microscope (SEM), and compositional purity was determined using energy dispersive x-ray spectroscopy (EDX). The Raman spectrum displays all atomic modes of vibration, providing information on phase, polymorphic crystallinity, and molecular interaction, as well as confirming the presence of all constituent elements. The ultraviolet visible spectrum research gives good bandgap energy for several optoelectronic devices. The impedance parameters have been measured using an impedance analyzer in a wide range of frequencies (102–106 Hz) and temperatures from 25 °C to 500 °C. The dielectric versus temperature and frequency analysis validates the Maxwell–Wanger type of dielectric dispersion. The impedance spectroscopy investigation indicates that the sample exhibits a negative temperature coefficient of resistance (NTCR), whereas the modulus analysis verifies a non-Debye type of relaxation process. The results of the ac conductivity research confirm a thermally activated relaxation process. Nyquist plot analysis reveals the NTCR character, which is well supported by Cole–Cole plots. The resistance versus temperature analysis supports the NTC thermistor nature, but the polarization–electric field (P–E) loop analysis reveals the presence of ferroelectric character, making it a strong option for temperature sensors and ferroelectric-related devices.

Physico-chemical properties of calendula flower extract in bitter almond oil elemental composition and microbiological purity

The study used bitter almonds (Amygdalus communis L. Varietas amara D.C.) obtained by cold pressing medicinal nails grown in Navoi region using oil (Calendula officinalis L.) - with the participation of flowers, the extraction process was carried out by maceration (in a ratio of 1:10). The resulting oil extract was studied by its elemental composition, chromatographic analysis of its fatty acids, microbiological purity, chemical and physical constants.

Influence of anodization time on Al2O3 nanoporous morphology and optical properties using energy band gap at room temperature

Development of nanoporous structures at room temperature using one-step anodization is well-known as a simple and cost-effective method for various industrial applications. In this study, we fabricated anodized alumina with nanoporous structures using oxalic acid as an electrolyte at an optimum potential voltage of 40 V. To understand the effect of anodization time on the morphology of the resulting nanostructures, and the anodization process was performed at different time durations, t = 40, 80, and 120 min. The results show that the anodization time influences the nanopore size. After comparison of morphologies of the developed nanostructures, we further discussed the material (elemental composition and phase purity) and optical characterization of Al2O3 nanoporous structure in comparison with the previous literature reports. The XRD and FTIR results confirm that the alumina phase dominates the aluminum phase. Our study also showed that Urbach energy (representing disorders associated with the electron transmission to determine the defects in materials via localized states) of the alumina phase is 0.47–0.520 eV, indicating fewer defects in the system. Further, the energy band gaps for the developed nanoporous structures were ∼2.83–2.90 eV (Tauc plot) and ∼2.27–2.31 eV (Absorption Spectrum Fitting). These results emphasize the potential of anodic alumina as a photoelectrode material for solar power-driven applications.

Ca2CuO3 perovskite nanomaterial for electrochemical sensing of four different analytes in the xanthine derivatives family

Nanostructured Ca2CuO3 was synthesized by chemical precipitation method and its application as a catalyst for electrochemical sensing of multi-analytes has been realized for the first time. The composition and phase purity of the synthesized Ca2CuO3 were studied by powder X-ray diffraction, X-ray photoelectron spectroscopy, Scanning and Transmission electron microscopy methods. Ca2CuO3 modified glassy carbon electrode (GCE) exhibited very high catalytic activity towards the oxidation of purine derivatives such as Xanthine (XA), Theophylline (TP), Uric acid (UA), and Caffeine (CF). The Ca2CuO3/GCE could be used over very wide linear ranges of 25 nM - 1.93 mM for UA, 50 nM - 1.62 mM for XA, 250 nM - 2.07 mM for TP and 1.75 μM - 2.11 mM for CF with the corresponding lowest detection limits of 12 nM, 36 nM, 105 nM and 1.72 μM respectively towards the selective determination of the chosen analytes. The developed non-enzymatic sensor was employed to determine all the target analytes in human urine and blood serum samples by standard addition method which displayed high recovery percentages. The developed sensor showed an excellent stability, high selectivity and good reproducibility at physiological pH of 7 making it suitable for pharmaceutical and diagnostic applications.

Enhancement of magnetic and dielectric properties in (1-x).BEFO+ x.NZF nano composites

Nanostructured Bi0.9Eu0.1FeO3 (BEFO), Ni0.6Zn0.4Fe2O4 (NZF), and (1-x).BEFO + x.NZF composites have been synthesized by traditional solid state reaction process with several dispersion techniques, where x = 0.0, 0.1, 0.3, 0.5, 0.7 and 1.0. X-ray diffraction confirms the perovskite, cubic, and mixed perovskite-spinel phase formation of BEFO, NZF, and (1-x).BEFO + x.NZF composites respectively. FESEM and EDX analysis confirm the nano grain size and compositional purity of the samples. The effect of sintering temperature (TS) on grain growth was studied at 600 °C and 850 °C, where the range of the average grain size is between (90–131) nm and (157–272) nm. The magnetic hysteresis loop properties of all the samples were measured by VSM, where the saturation magnetization (MS) of BEFO increased from 10.31 emu/g to 50.54 emu/g with increasing NZF content. The increment of NZF content also modified other magnetic properties of (1-x).BEFO + x.NZF composites such as coercive force (HC), retentivity (Mr), magnetic moment (nB), and anisotropy constant (K). The frequency dependent permeability measurements show that the initial permeability (μ') was stable in a long frequency range up to 108 Hz and that the magnetic loss tangent (tanδM) decreased with increasing NZF content. The dielectric characteristics and AC resistivity of the composites were measured by an impedance analyzer over a wide frequency range (1 Hz–100 MHz). All the dielectric properties of the synthesized samples show excellent stability up to a long frequency region and vary sharply with increasing NZF content. From the optimization, 0.9 BEFO + 0.1 NZF composite has the highest permeability and dielectric values with the least amount of dielectric and magnetic losses. All the investigated composites might be strong candidates as multiferroic materials with strong magnetic and electric characteristics.

Structural, complex dielectric, Ac conductivity and impedance properties of Mn3-xCrxTeO6 (x = 0.02, 0.04, 0.06 and 0.08) compounds

In this communication, the synthesis of polycrystalline Mn3-xCrxTeO6 (MCTO) (x = 0.02, 0.04, 0.06 and 0.08) compounds is carried out using the standard high-temperature solid-state reaction (SSR) method. The X-ray Diffraction (XRD) technique revealed the trigonal (hexagonal axes) crystal structure of MCTO compounds. The doping of Chromium (Cr) on the Mn site does not affect the structure of the compound. The compositional purity and morphological observations are also investigated. Dielectric parameters are examined throughout a wide frequency range. Detailed investigation obtained by theoretical fitting of the cole-cole model revealing a non-Debye type relaxation mechanism which is also evident from the complex modulus studies. An investigation on electrical conductivity is carried out by conceptually fitting experimental data using a power law and indicates a Correlated Barrier Hopping mechanism in MCTO compounds as the cause of conduction. The resistance and capacitance were validated by impedance analysis, and the effect of grains and grain boundaries was also studied accordingly. In-depth, this study demonstrates an effective synthesis approach and a thorough examination of Cr-doped Mn3TeO6 multiferroic compounds, potentially providing fundamental attributes to investigate their applications in various fields of multiferroics.

Green synthesized Ag decorated CeO2 nanoparticles: Efficient photocatalysts and potential antibacterial agents.

Implication of natural resources for manufacturing of nanoparticles is sustainable, economical and contaminant free approach towards ecological and medical applications. Herein, CeO2 and Ag/CeO2 nanoparticles are green synthesized from Morinda tinctoria plant extract. The phase structure, surface morphology, optical identity, Ce(III) and Ce(IV) valency of the synthesized CeO2 and Ag/CeO2 nanoparticles are explored. The X-ray diffraction analysis indicated the formation of cubic phase CeO2 and cubic silver decorated CeO2 nanoparticles. Fourier transform infrared (FTIR) spectroscopy revealed the metal decoration of CeO2 nanoparticles, metal-oxygen stretching, indicating the plant molecules reduction and stabilization. UV–visible spectroscopy shown the decreased band gap owing to silver modification. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) micrographs displayed spherical morphology of the nanoparticles. Elemental composition and sample purity is assessed by energy dispersive spectroscopy (EDS). Double oxidation of Ce, double splitting energy of Ag and lattice oxygen are observed from X-ray photoelectron spectroscopy (XPS). Photocatalytic activity of Ag/CeO2 exposed the enhanced photocatalytic activity up to 94% where CeO2 nanoparticles gave 60% degradation of bromophenol blue (BB). The plasmonic decoration of silver on the ceria surface induced the charge separations and free radical reactions. Moreover, Ag/CeO2 nanoparticles are seen as superior antibacterial agents than CeO2 towards both E.coli and S.aureus. Hence, the silver decorated metal oxide photocatalyst successfully degraded the BB dye and inactivated the bacterial strains. This report established a future research in green synthesis of multipurpose metal nanoparticles.