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Inorganic photocatalytic materials exhibiting a highly efficient response to ultraviolet-visible light spectrum have become a subject of widespread global interest. Nanocomposite metal oxides, particularly Nickel Oxide (NiO) and Zinc Oxide (ZnO), have gained attention for their diverse applications in gas sensing and photocatalytic processes. In this work, ZnO-NiO (ZnO_0.6NiO_0.4 and ZnO_0.4NiO_0.6) binary nanocomposites were synthesized by hydrothermal technique. The binary nanocomposites were analyzed by UV-Visible spectrophotometer, X-ray diffraction (XRD), photoluminescence (PL), Fourier transform infrared spectrophotometer (FTIR), energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The XRD pattern revealed that the nanocomposites, the peaks of both ZnO and NiO are present indicating the presence of both crystal structures hexagonal wurtzite and cubic. The miller indices, crystallite size, microstrain and dislocation density were determined from the XRD plot. FESEM and TEM analyses showed the spherical morphology of the synthesized composites with an approximate size of 10nm. The detailed analysis of ZnO–NiO binary nanocomposite sensor characteristics in terms of sensitivity, selectivity, response and recovery time were carried out and the nanocomposites were found to be highly sensitive to CO₂ 100 ppm at 350^∘C and Cl₂ at 200^∘C. The photocatalytic degradation outcome showed 52% degradation of methylene blue at 10 ppm and 90w/m². These results suggest the potential utility of these binary nanocomposites in photocatalytic applications for the degradation of organic pollutants.

In this research work, nanocomposites of CuO/TiO₂ were initially fabricated using drop casting method. Later on, these nanocomposites were irradiated for the first time by a beam of Argon ions (Ar${}^{+})$ by keeping the fluence rates of $1\times 10^{14}$ ions cm${}^{-2}$, $1\times 10^{15}$ ions cm${}^{-2}$, and $1\times 10^{16}$ ions cm${}^{-2}$, respectively. In order to observe structural and optical properties of un-irradiated and irradiated nanocomposites, Raman Spectroscopy, Energy Dispersive X-ray (EDX), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Photoluminescence (PL) and Diffuse Reflectance Spectroscopy (DRS) analysis were performed. From Raman analysis, vibration modes confirmed the presence of different phases of TiO₂ and CuO. EDX analysis clearly demonstrates the presence of Cu, Ti, and O peaks. SEM images depict agglomerated spherical nanoparticles having diameters in the range of 40–94nm. From TEM analysis, mean diameter of 56.1nm is observed for unirradiated and 33.7nm for Ar${}^{+}$ irradiated CuO/TiO₂ nanoparticles in nanocomposite for fluence rates of $1\times 10^{14}$ ions cm${}^{-2}$, $1\times 10^{15}$ ions cm${}^{-2}$, and $1\times 10^{16}$ ions cm${}^{-2}$. HR-TEM and SAED images represent the polycrystalline nature of these nanocomposites.

Among the three peaks of PL spectra in UV–Visible region, first two peaks were observed at 356nm, and 419nm but the third peak is little shifted from 488nm with the increase in fluence rate. Values of band gap are reduced from 3.29eV to 3.17eV as the fluence rate is increased, as calculated from results of diffuse reflectance spectroscopy.

Novel nanoprism-shaped manganese-doped copper sulfide (Mn–CuS) was fabricated by two-phase colloidal method (Mn percentages = 0%, 1%, 3%, and 5%). The Mn–CuS was analyzed by XRD, FTIR, UV–Vis spectrometer, and TEM. The XRD shows that the hexagonal covellite copper sulfide peaks appeared at 2$\theta =47.9^{\circ },31.9^{\circ },47.8^{\circ }$, and $31.8^{\circ }$ for 0%, 1%, 3%, and 5% respectively, and orthorhombic chalcocite copper sulfide appeared at the peaks that are corresponding the planes (412), (275), (029) and (106). According to UV–Vis analysis, the optical absorption of manganese-doped copper sulfide 0%, 1%, 3%, and 5% clearly appeared in the UV–Vis region at 518, 440, 478, and 477nm respectively, and there are broad peaks for localized surface plasmon resonances (LSPR) of CuS located at 970, 1061, 1002, and 1006nm for Mn–CuS 0%, 1%, 3%, and 5%, respectively. The favored nanoprism-shaped sample (manganese-doped copper sulfide 1%) was coated with gum Arabic (GA) in order to decrease the cytotoxicity and enhance the biocompatibility. The antibacterial activity of manganese-doped copper sulfide and GA@Mn–CuS 1% nanostructure toward Staphylococcus aureus and Escherichia coli bacteria was determined by inhibition zone. It was found that the fabrecated Mn–CuS 1% nanoprisms were more active toward both E. coli and S. aureus bacteria and the doping enhanced the antibacterial activity.

Polycrystalline ingots of CuInSe₂ and CuIn₃Se₅ were synthesized by melt-quench technique starting from the stoichiometric mixture of constituent elements. X-ray Diffraction (XRD) studies confirmed the single-phase nature of the materials. Compositional analysis by Particle Induced X-ray Emission (PIXE) showed that the compounds are near stoichiometric. Thin films of CuInSe₂ and CuIn₃Se₅ were grown from pre-synthesized CuInSe₂ and CuIn₃Se₅ powders. The films were polycrystalline, single-phase and near stoichiometric in nature, as indicated by Transmission Electron Microscopy (TEM) and PIXE studies.

ZnO nanobamboos and nanowires with diameters of 10–30 nm and lengths of 2–4 μm have been prepared by laser ablation in vacuum with precisely controlled pressure, growth and post-annealing temperature. XRD results show the annealed sample is hexagonal ZnO. Low-magnified TEM observation reveals the annealed sample includes ZnO nanobamboos and nanowires. High resolution TEM image and electron diffraction pattern confirm that the structure of ZnO nanobamboo is regular stacking of Zn and O layers with high crystal quality. The growth direction is determined as along [001] direction (c axis). TEM observations confirm that the formation of bamboo-shape ZnO is due to the stacking fault and cleavage. The bundle of those stacking faults seems to be the origin of the black contrast at the nodes. The uniformity of chemical composition for the nanobamboos is identified by EDS profiles. A strong-narrow UV band centred at 390 nm and a weak-broad green band centred at 515 nm are observed at room temperature in the PL spectrum recorded from the annealed ZnO nanobamboos and nanowires.

The objective is to characterize the effect of the bimodal distribution of rubber particles and its blend ratio on the mechanical properties of the thermoplastic polypropylene blended with two different styrene-ethylene-butadiene-styrene tri-block copolymer (SEBS) at the intermediate and high strain rates. Tensile tests are conducted at the nominal strain rates from 10⁻¹ to 10² (1/sec). Phase morphology is investigated to estimate the bi-modal rubber particle size distribution. In addition, the in-situ observation is conducted during uniaxially stretching within transmission electron microscopy (TEM) step by step to investigate the deformation events depending on the elongation of samples. The elastic modulus increased gradually as the blend ratio of large rubber particle increased. An increase in the rupture strain was found for the bimodal rubber-particle distributed blend system where the blend ratios of small rubber particle and large rubber particle were the same. This is because the smaller particles dominant blend systems show the band-like craze deformation while the localized plastic deformation is taken place in the larger particles dominated blend systems. The synergistic effect of these rubber particles gives rise to a strong increase in the ductility of these bimodal rubber-particle distributed polypropylene systems.

Nanocrystalline Cu particles were prepared by mechanochemical reduction of cuprite (CU₂O) with graphite in a high-energy ball mill. In order to gain an understanding into the possible mechanisms, the kinetic of the process was investigated using Johnson-Mehl-Avrami (JMA) model. It can be seen that theoretical calculation agrees well with experimental data. It was found that the most important effect of mechanical activation is the formation of the lattice defects and grain boundaries in addition to activated fresh surface areas during milling, which promote the reduction process. The Cu nanopowder was characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD and TEM results showed the nano-structure nature of the product processed under the synthesis conditions; the crystallite size was measured almost 30 nm in the 30 h milled powders.

A series of Fe_2-xAl_xCoO₄ ferrite nanoparticles have been synthesized by sol-gel method. Powder X-ray diffraction (XRD), thermo gravimetric (TG) and differential thermal analysis (DTA), transmission electron microscopy (TEM) and IR spectroscopy analysis were employed to study structural and morphological characterization of these ferrite nanoparticles. The effect of substitution of Fe³⁺ by Al³⁺ ions on the structural properties of cobalt ferrite nanoparticles was investigated. The crystallite (D) is found in the range 39 nm to 6 nm, which decreases with increasing aluminum content. The values of lattice parameters (a), X-ray density (d_x), hopping length (L_A, L_B) decreases with aluminum content. The tetrahedral bond (d_AX), octahedral bond (d_BX), tetra edge (d_AXE) and octa edge (d_BXE) (shared and unshared) showed the linear decrease with the increasing aluminum content x. IR spectroscopy analysis revealed the chemical and structural changes taking place in the combustion reaction.

Epitaxial growth of non-polar thin films (a-plane ZnO) on sapphire (r-plane sapphire) were successfully implemented through metal organic chemical vapor deposition (MOCVD) and radio-frequency sputtering, respectively. For ZnO film deposited by sputtering, the growth temperature and the flow ratios of argon to oxygen were shown to significantly influence the crystalline quality and surface morphology of ZnO films. Flat surface ZnO epitaxial film can be grown by MOCVD. The epitaxial relationship between ZnO and sapphire substrate is and . The full width at half maximum (FWHM) of X-ray rocking curve for reflection peak depends on the orientation of X-ray beam toward sample surface. SEM and AFM observations show the surface morphologies of ZnO epilayers exhibit a stripe-like pattern along ZnO [0001] direction. The higher growth rate along ZnO [0001] and in-plane anisotropic lattice mismatch between a-plane ZnO and r-plane sapphire might result in the formation of such stripes.

The aim of present research is to study the influence of sintering temperature on the preparation of nanocrystalline Yttrium Iron garnet (YIG) with improved magnetic properties. The nanocrystalline YIG powders were synthesized using Microwave-Hydrothermal (M-H) method. The synthesized powders were characterized using X-ray diffraction (XRD) and Transmission Electron Microscope (TEM). The powders were sintered at various temperatures using microwave sintering method. The sintered samples were characterized using XRD. The complex permeability, dielectric constant and loss tangent of sintered YIG ceramic were also measured and discussed in this paper

Specimens of nanocrystalline pure gold were prepared by the gas deposition method. The formation of helium bubbles in the specimens and their annealing behavior were studied in order to confirm their effect on thermal stabilities of grain size and mechanical properties. The specimens with 10-25nm mean grain size were analyzed by transmission electron microscopy and X-ray diffraction methods. Spherical helium bubbles, about 5nm in diameter, were formed, the same as in the case of helium ion implantation. After annealing at 573K for 1h in vacuum, most of the bubbles had not disappeared and some were trapped at the grain boundaries. Larger numbers of bubbles were trapped at grain boundaries in the specimens with high thermal stability than for low thermal stability specimens. Helium bubbles trapped at grain boundaries can be considered as local barriers to grain growth and to contribute to thermal stability of mechanical properties.

In this letter we report on successful preparation and characterization of anisotropic gold nanocrystals bio-synthesized by reduction of aqueous chloroaurate ions in pelargonium plant extract. The nanocrystals have been characterized by means of Transmission Electron Microscopy (TEM), UV-VIS absorption spectroscopy and tapping mode atomic force microscopy (TM-AFM). Using these investigation techniques, the successful formation of anisotropic single nanocrystals with the preferential growth direction along the gold (111) plane has been confirmed. The high detail phase images could give us an explanation concerning the growth mechanism of the nanocrystals.

The effects of the reducing agents of hydrazine (H₄N₂), sodium borohydride (NaBH₄), and triethylsilane (C₆H₁₅Si) on the morphologies of gold nanoparticles in the poly(styrene-b-4-vinylpyridine) micelle were studied using small-angle X-ray scattering (SAXS), UV/visible spectroscopy and transmission electron microscopy (TEM). "Cherry" morphology was found in the gold nanoparticles reduced by hydrazine while "raspberry" morphology was found in the gold nanoparticles reduced by sodium borohydride. Hydrazine was more effective in reducing gold nanoparticle in the core of the PS-b-P4VP micelle than sodium borohydride and triethylsilane. The nanoparticles reduced by hydrazine were confined in the core and more regular than those reduced by sodium borohydride and triethylsilane. The possible mechanism leading to these morphological differences was also discussed.

Nanocrystalline Co${}_{0.5-x}$Zn${}_{0.5}$Cu${}_x$Fe₂O₄ spinel ferrites were prepared by autocombustion method with citric acid as fuel. Paramagnetic divalent copper ions substituted in place of ferromagnetic cobalt ions resulted in the modifications of structural and magnetic properties of the system. All samples were characterized with X-ray diffraction technique for structure determination. Crystallite sizes were calculated using Williamson–Hall plot and size–strain plots. Cation distribution and all other structural parameters were presented. Transmission electron microscopy measurements were done for x = 0 and x = 0.15 and they showed well-developed spherical particles with average sizes of 35 nm and 48 nm. Morphological studies were performed and grain growth was observed to be increased with copper concentration. EDAX measurements revealed the stoichiometric proportions of the samples as per the chemical composition. Mid-IR spectroscopy was used to characterize the spinel phase and displayed two characteristic absorption bands in all samples with a slight shift. M–H loops were recorded using vibrating sample magnetometer at room-temperature and highest saturation magnetization was observed to be 50.2 emu/g for the base (x = 0) sample. Magnetocrystalline anisotropy was discussed with the help of magnetocrystalline anisotropy constant K₁.

Calcium phosphate based biomaterials play important roles in clinical applications. Calcium pyrophosphate (CPP), a kind of calcium phosphate, can be used as a bone substitution material as well as a bone graft. Because of its similarity to inorganic component of bone and teeth it can be used for surface coating of metallic dental and orthopedic implants. In the present study, calcium pyrophosphate dihydrate (CPPD) nanoparticles were synthesized using surfactant mediated approach. Crystalline nature and average crystallite size was studied using Powder XRD. The CPPD nanocrystallites were found to be triclinic from powder XRD. The TEM study indicated that CPPD nanoparticles were in the range of 13 nm to 20 nm. The presence of various bonds was confirmed by FTIR spectroscopy. The amount of water of hydration and the thermal stability was studied by thermogravimetry. The variations of various dielectric parameters with the frequency of applied field in 3.2 kHz to 32 MHz range and within a temperature range from 60°C to 120°C were studied. The formation of other phases such as β-CPP and α-CPP on heating of CPPD at 900°C and 1250°C, respectively, were studied by the Powder XRD. The results are discussed.

Europium doped CaAl₂O₄ nanocones have been grown first time by thermal evaporation method. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to analyze the morphology, size and crystal structure of the nanocones. The body of the nanocones are about 2–20 μm in length and their diameters are 200 nm to 1 μm at one end and tapers off to a ~ 40–200 nm at the tip end. The as-synthesized nanocones are single crystalline in monoclinic structure and grow along the [010] direction and the normal direction of (100) and (001). The room temperature photoluminescence (PL) and cathodoluminescence (CL) spectrum measurement reveals that CaAl₂O₄:Eu²⁺ nanocones emit light at about 440 nm.

Continuous silicon carbide fiber-reinforced silicon carbide (SiC_f/SiC) composites are promising structure candidates for future fusion power systems such as gas coolant fast channels, extreme high temperature reactor and fusion reactors, because of their intrinsic properties such as excellent mechanical properties, high thermal conductivity, good thermal-shock resistance as well as excellent physical and chemical stability in various environments under elevated temperature conditions. In this study, bonding of tungsten and SiC_f/SiC was produced by hot-press method. Microstructure analyses were performed using SEM and TEM.

Rare earth oxides have been extensively investigated due to their fascinating properties such as enhanced luminescence efficiency, lower lasing threshold, high-performance luminescent devices, drug-carrying vehicle, contrast agent in magnetic resonance imaging (MRI), up-conversion materials, catalysts and time-resolved fluorescence (TRF) labels for biological detection etc. Nanocomposites of silica gadolinium oxide have been successfully synthesized by sol–gel process using hydrochloric acid as a catalyst. Gd(NO₃)₃⋅6H₂O and tetraethyl orthosilicate (TEOS) were used as precursors to obtain powdered form of gadolinum oxide:silica (Gd₂O₃:SiO₂) composite. The powdered samples having 2.8 mol% Gd₂O₃ were annealed at 500°C and 900°C temperature for 6 h and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and transmission electron microscope (TEM). The effect of annealing on the phase evolution of the composite system has been discussed in detail. It was found that the sintering of gadolinium precursor plays a pivotal role to obtain crystalline phase of Gd₂O₃. Cubic phase of gadolinium oxide was developed for annealed sample at 900°C (6 h) with an average grain size ~12 nm.

In this paper, third generation SiC fiber material irradiated with the 410 MeV energy of ${}^{112}{\mathrm{\text{Sn}}}^{26+}$ ion at 173 K was analyzed by Raman spectroscopy, X-ray diffraction (XRD) and transmission electron microscope (TEM). Raman spectroscopy, TEM and XRD data show modifications in the local structure of irradiated SiC fibers. Although highly disordered SiC grains were observed in appearance, no evidence of amorphization was found. After the Sn ions irradiation and XRD, two diffraction peaks disappeared, which showed that the rich Si and C could be further combined in $1.5\times 10^{15}$ ions/cm² dose irradiation condition. This result mainly explains the electron damage and the nuclear damage process in SiC fibers, leading to the recombination or migration of defects.

Siderite or ferrous carbonate $({\mathrm{\text{FeCO}}}_3)$ is a well-known mineral and finds applications in various fields such as dietary supplement to treat anemia and in petroleum drilling fluids for ${\mathrm{\text{H}}}_2\mathrm{\text{S}}$ removal. The FeCO₃ nano-particles are synthesized by hydrothermal method using aqueous solutions of iron sulfate, ascorbic acid and ammonium carbonate with a molar ratio of 1:1:3, respectively, and heating at $140^{\circ }$C for 1.5 h in Teflon-lined stainless steel autoclave. The recovered sample is characterized by several techniques. The powder XRD indicates the hexagonal crystal system and the average crystallite size of 17.32 nm are obtained from the Scherrer’s formula and 18.98 nm is obtained from the Williamson and Hall formula. The TEM images suggest the spherical nature of the nano-particles. The EDX confirms the elemental presence of iron, carbon and oxygen. The impedance and dielectric studies are carried out within 20 Hz–2 MHz range at room temperature. The complex impedance plot, i.e. the Nyquist plot, is composed of one semicircle indicating the contribution from the grain only. The Jonscher’s power-law is applied to AC conductivity data. The VSM data at room temperature and at low temperature, i.e. 20–300 K range, suggests a weak antiferromagnetic nature of the sample.