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Hydrogenated carbon nitride films have been synthesized on Si (100) by DC reactive sputtering with RF bias. These films are characterized by transmission electron microscopy and atomic force microscopy. Hydrogenated carbon nitride films have low surface roughness. At low hydrogen fraction, the films include small crystallites. High hydrogen fraction promotes the films to be amorphous. The resistivities of the films are measured, which range from 6.35×10⁵ to 1.16×10⁸ Ω·cm. The measured resistivity results indicate that the hydrogenated carbon nitride films have semiconductive properties. The resistivity largely depends on the bonding configurations. Effects of H₂ fraction, target current and substrate bias are investigated. All these deposition parameters have influence on the resistivities. High C—H, N—H and C—NH bond fractions result in high resistivity.

A comprehensive ab-initio investigation of the stability, structural, electronic, optical and Raman-active properties has been performed for the small diameter armchair carbon nanotubes. A number of new features not discussed earlier are observed in the present study. The binding energies (BEs) for the ultrathin nanotubes with respect to the graphine sheet are negative and the magnitude of the negative BE decreases with the diameter of the tube approaching zero for the graphine sheet. The separation between the two van Hove singularities (vHs) around the Fermi level increases with the diameter of the tube. The main absorption arises from the transitions between the states at nonzero values of k_z lying in the range 0.38–0.50. There is a large variation in the magnitude of the optical matrix-element with the wave vector. The energy range of the strong optical absorption increases with the diameter of the tube. The presently predicted absorption and the RBM frequencies are in good agreement with the available experimental data. The variation of the radial breathing mode (RBM) frequency with diameter "d" of a tube obeys a relation which is very close to an experimentally determined relation obtained for a number of wide semiconducting nanotubes possessing a wide range of chiral angles.

Nanocrystalline thin films of CdSe have been synthesized from an acidic solution containing CdSO₄ and SeO₂ by a cathodic electrodeposition technique under galvanostatic condition. The crystal structure and morphology have been investigated by Grazing angle X-Ray Diffraction (GXRD), Transmission Electron Microscopy (TEM) and optical microscopic measurement. The X-Ray and TEM diffraction patterns of the deposit reveal a bimodal size distribution with the presence of cubic (zinc blende) phase in the deposit. The particle sizes have been estimated from GXRD measurement found to be 4 nm to 6 nm, comparable to that obtained from TEM analysis. A Branched Fractal Pattern (BFP) in CdSe nanocrystals has been observed by optical microscopy, suggesting a diffusion-limited aggregation growth mechanism with fractal dimension 1.69 ± 0.04.

Titanium oxide films were deposited on Si and quartz substrates by RF magnetron sputtering of titanium target under various oxygen partial pressures. The films were annealed in air at different temperatures and the influence of annealing temperature on the structural and optical properties was studied. The XPS studies revealed that the films formed at oxygen partial pressure of 2 × 10^-2 Pa were nearly stoichiometric. The as-deposited films were amorphous, the films annealed at 573 K were anatase, while those annealed at 973 K were mixed anatase and rutile phases of TiO₂. The as-deposited films showed an optical bandgap of 3.32 eV while those annealed at 973 K was 3.19 eV.

Ag₂Cu₂O₃ films were deposited on glass substrates held at 303 K by RF magnetron sputtering of Ag₇₀ Cu₃₀ target at different oxygen partial pressures and substrate bias voltages. Single phase Ag₂Cu₂O₃ films were formed at an oxygen partial pressure of 2 × 10^-2Pa. The films deposited at oxygen partial pressure 2 × 10^-2Pa and substrate bias voltage of -60 V were nanocrystalline with crystallite size of 20 nm, low electrical resistivity of 3.9 Ωcm and optical band gap of 2.02 eV.

Co-Cu alloy thin films were electrodeposited on a fluorine-doped tin oxide (FTO)-coated conducting glass substrate from a sulfate solution at applied potentials ranging from -0.7 V to -1.3 V versus saturated calomel electrode (SCE). Voltammetric studies showed that the composition and, consequently, the potential dissolution of Co depend greatly on the applied potentials. The compositional measurement, which was made using an atomic absorption spectroscopy (AAS), demonstrated that the Co content of the films considerably increases as the applied potentials to tend toward negative values. The SEM study showed that a granular structure of the electrodeposited Co-Cu. X-ray diffraction measurements showed that all peaks of the Co-Cu films were consistent with those of a typical Co hcp and Co-fcc mixed phase and Cu-fcc phase at low potential. The increase of the applied potential induces a decrease in the grain size and the lattice constant. The magnetic hysteresis measurements carried out by an alternating gradient force magnetometer (AGFM) revealed the existence of a ferromagnetic behavior with an in-plane easy magnetization axis for the film deposited at -1.1 V versus SCE. However, for applied potentials of -1.2 V and -1.3 V, we observe the coexistence of a dominant in-plane easy magnetization along with a perpendicular one.

Naturally derived biopolymers have been widely used for biomedical applications such as drug carriers, wound dressings, and tissue engineering scaffolds. Chitosan is a typical polysaccharide of great interest due to its biocompatibility and film-formability. Chitosan membranes with controllable porous structures also have significant potential in membrane chromatography. Thus, the processing of membranes with porous nanoscale structures is of great importance, but it is also challenging and this has limited the application of these membranes to date. In this study, with the aid of a carefully selected surfactant, polyethyleneglycol stearate-40, chitosan membranes with a well controlled nanoscale structure were successfully prepared. Additional control over the membrane structure was obtained by exposing the suspension to high intensity, low frequency ultrasound. It was found that the concentration of chitosan/surfactant ratio and the ultrasound exposure conditions affect the structural features of the membranes. The stability of nanopores in the membrane was improved by intensive ultrasonication. Furthermore, the stability of the blended suspensions and the intermolecular interactions between chitosan and the surfactant were investigated using scanning electron microscope and Fourier transform infrared spectroscopy (FTIR) analysis, respectively. Hydrogen bonds and possible reaction sites for molecular interactions in the two polymers were also confirmed by FTIR analysis.

We have investigated the crystal structure, the microstructural and morphological characteristics, as well as the magnetic properties of Co nanoparticles (NPs) synthesized by a hydrothermal method. A series of samples has been elaborated for different concentrations of sodium hydroxide. The analysis of X-ray diffraction patterns, using two different wavelengths, has evidenced the coexistence of both $\alpha$-Co and $\beta$-Co phases in the samples. The lattice parameter for both phases is in good agreement with those values expected for their bulk Co counterparts; the grain sizes of NPs were found to be dependent on the NaOH concentration. The scanning electron microscope micrographs show that Co NPs are agglomerated forming micrometer-sized entities whose shape evolves, indicating that the synthesis process affects the morphology of the powdered samples. Magnetic measurements indicate that the coercivity is slightly larger, $H_C>200$ Oe, for Co NPs with dendritic-like shape, probably due to an increase in the magnetocrystalline anisotropy.

Magnetometry and atomic force microscopy (AFM) were used to study the magnetic and structural properties of the R–Fe–B-type (R = Y, Nd, Gd, Ho) alloys. The alloys were synthesized by means of induction melting. The nanocrystalline state of the R–Fe–B-type alloys was reached, mainly, by melt spinning (MS). A multistage treatment of R–Fe–B-type alloys, which included severe plastic deformation of melt-quenched ribbons and subsequent heat treatment, was also used. The surface morphology of samples was studied in detail to interpret the observed magnetic hysteresis loops of the samples. It was found that the type of rare earth ion and treatment methods had the most important influence on the microstructure and magnetic properties.

The structural, electronic, magnetic, and optical properties of Au, Cu, Cr, Mn, Co, Ni, and Fe atoms doped 13-atom silver clusters were investigated by the density functional theory (DFT) in the theoretical frame of the generalized gradient approximation (GGA) exchange-collection function. The results show that all the ground state structures of Au, Cu, Cr, Mn, Co, Ni, and Fe atoms doped 13-atom silver clusters are icosahedral, respectively. The Au atom doped on the surface of Ag${}_{13}$ cluster is stable, while other atoms doped in the center of Ag${}_{13}$ cluster are stable. The electronic stability order from high to small is Ag${}_{12}$Cr₁, Ag${}_{12}$Cu₁, Ag${}_{12}$Co₁, Ag${}_{12}$Fe₁, Ag${}_{12}$Au₁, Ag${}_{12}$Mn₁, Ag${}_{12}$Ni₁. Their magnetic moments are not only related to the doping atom but also the doping location of the atom. The magnetic moments of the Cu, Au, Mn, Co, Ni, Fe, and Cr atoms doped in the Ag${}_{13}$ cluster are 5.0, 3.0, 1.0, 3.0, 4.0, 2.0, and 0.0${\mu }_B$, respectively. Compared with the optical absorption spectrum of the Ag${}_{13}$ cluster, the Au, Cr, and Mn atoms doped the Ag${}_{13}$ cluster leading to blue shift, and the Cu, Co, Ni, and Fe atoms doped the Ag${}_{13}$ cluster resulting in red shift. These studies provide a theoretical basis on applications for clusters in electronic, magnetic, and optical devices.