Segregation of tin on (111) and (100) surfaces of copper

Surface segregation of Sn in Cu is measured at (111) and (100) surfaces by means of AES and LEED. In the case of at temperature measurements and no cosegregation of impurities occurring, equilibrium segregation is accomplished for Sn bulk concentrations between 40 and 4300 at ppm and temperatures of 800 to 1230 K. The maximum segregation level of Sn corresponds to a (√3 × √3)R30° structure for the (111) surface and a p(2 × 2) structure for the (100) surface. For theoretical analysis, the Langmuir-McLean equation has to be modified. No difference in segregation enthalpies for both surface orientations is found within the experimental error. The mean segregation enthalpy is determined to ΔH = ?(53 ± 5) kJ/g-atom.     

Synthesis and characterization of copper oxide (I) nanoparticles produced by pulsed sonoelectrochemistry

Cu(2)O nanopowders have been prepared by ultrasound-assisted electrochemistry with a potentiostatic set-up. Their composition has been determined by X-ray diffraction and energy dispersive X-ray spectroscopy. Transmission electron microscopy and centrifugation analyses indicate that the nanopowders consist of agglomerates of variable nanometric diameter grain. Most of particles have a diameter of 8 nm whatever the electrodeposition potential. The influence of the parameters of electrochemical and ultrasonic pulses on the particle diameter was also studied. The specific surface areas determined by Brunauer-Emmet-Teller (BET) model are very high with a value close to 2000 m(2)g(-1).     

Interfacial interaction in a composite based on multi-walled carbon nanotubes and amorphous tin oxide

The specific features of changes in the electronic structure of multi-walled carbon nanotubes (MWCNTs) due to the interaction with an amorphous tin oxide in the SnO_x/MWCNT composite formed by magnetron sputtering have been investigated using X-ray spectroscopy. It has been shown that the formation of chemical bonds responsible for significant changes in the local and electronic structures of the outer layers of MWCNTs occurs at the boundaries of the “amorphous oxide/MWCNT” contacts. The vacuum annealing of the composite leads to the disturbance of the chemical interaction at interfaces of the composite and to a partial recovery of the local structure of the outer layers of MWCNTs. A decrease in the amount of oxygen in the tin oxide under vacuum annealing conditions causes an increase in the number of unpaired Sn 5s electrons, which, in turn, enhances the charge transfer through the interfaces in the composite and leads to a splitting of the π^*-subsystem of the outer layers of MWCNTs.     

Sonochemical syntheses of a nanoparticles cadmium(II) supramolecule as a precursor for the synthesis of cadmium(II) oxide nanoparticles

Nanoparticles of a three-dimensional supramolecular Cd(II) compound, [Cd(L)(2)(H(2)O)(2)] (1), (L(-)=1H-1,2,4-triazole-3-carboxylate), have been synthesized by a sonochemical process and characterized by scanning electron microscopy, X-ray powder diffraction, IR spectroscopy and elemental analyses. The thermal stability of compound 1 in both its bulk and nano-size has been studied by thermal gravimetric (TG) and differential thermal analyses (DTA) and compared with each other. Concentration of initial reagents effects on size and morphology of nano-structured compound 1, have been studied. Calcination of the single crystals and nano-sized compound 1 at 650°C under air atmosphere yields CdO nanoparticles.     

Self-assembly growth and electron work function of copper phthalocyanine films on indium tin oxide glass

Organic semiconductor materials are becoming a promising subject of not only scientific interest but also potential applications in the field of new energy resources. In this study, the copper phthalocyanine (CuPc) films as an excellent organic semiconductor were self-assembly grown on indium tin oxide glass by electrodeposition, the structural and electronic properties were investigated using various techniques. The results demonstrated that ordered α-form crystalline CuPc films were obtained. The decrease of electron work function of CuPc films with the increase of film thickness was found, which was obviously dependent on the surface morphology. The understanding of these behaviors of CuPc films will be significant for designing related photoelectric devices.     

Work function of sol-gel indium tin oxide (ITO) films on glass

Indium tin oxide (ITO) films (physical thickness, 250-560 ± 25 nm) were deposited on soda lime silica (SLS) glass and silica layer coated (∼200 nm physical thickness) SLS glass substrates by sol-gel technique using alcohol based precursors containing different In:Sn atomic percentages, namely, 90:10, 70:30, 50:50, 30:70. Cubic phase of In₂O₃ was observed up to 50 at.% Sn while cassiterite SnO₂ phase was observed for 70 at.% Sn. Work function of the films was evaluated from inelastic secondary electron cutoff of ultraviolet photoelectron spectroscopy (UPS) energy distribution curve (EDC) obtained under two experimental conditions (i) as-introduced (ii) after the cleaning of the surface by sputtering. Elemental distribution and the presence of oxygen containing contaminant and carbon contaminant of the samples were done by XPS analysis under same conditions. The work function changed little due to the presence of surface contaminants. It was in the range, 3.9-4.2 eV (±0.1 eV).     

Isolated tin fluoride molecules in a copper lattice

A Mössbauer absorber was made by simultaneous evaporation of copper and implantation of¹¹⁹Sn, and postimplantation of F. A large fraction of Sn⁴⁺ was formed, assigned to the formation of SnF₄.     

反应离子镀制备ITO膜

采用反应离子镀新工艺成功地在K9玻璃上制备了ITO(Indium Tin Oxide)透明导电膜,所制备的ITO膜在550～600nm波长范围内,典型的峰值透过率为89%,面电阻为34Ω/□。     

Sonochemical syntheses of a new nano-plate cadmium(II) coordination polymer as a precursor for the synthesis of cadmium(II) oxide nanoparticles

Nanoplates of the three-dimensional coordination polymer, {[Cd(3)(3-pyc)(4)(N(3))(2)(H(2)O)](n) (1), 3-pyc(-)=pyridine-3-carboxylate), have been synthesized by a sonochemical process and characterized by scanning electron microscopy, X-ray powder diffraction, IR spectroscopy and elemental analyses. Cadmium(II) oxide nanoparticles were prepared from thermal decomposition in oleic acid and direct calcination of compound 1 at different temperatures. The thermal stability of nano-sized compound 1 was studied by thermal gravimetric (TG) and differential thermal analyses (DTA). Results show that the size and morphology of the CdO nanoparticles are dependent upon the particles size of compound 1 and the thermolysis temperature. A decrease in the particle size of compound 1 leads to a decrease in the particle size of the CdO, while an increase in the processing temperature leads to an increase in the particle size of the produced cadmium(II) oxide nano-particles.     

Synthesis and characterization of indium–tin oxide (ITO) nanoparticles

Synthesis and characterization of ITO nanoparticles were investigated in the present study. To synthesize the ITO nanoparticles flame spray pyrolysis was introduced. The average particle diameter increased with an increase in the molar concentration of the precursor. Raising the maximum flame temperature by controlling the gas flow rates also led to an increase in the average diameter of the particles. The crystalline ITO nanoparticles were synthesized, and their average primary particle diameters ranged from 11 to 20 nm. ITO thin films were prepared with a sol consisted of the ITO nanoparticles and a polymer binder. Effect of average particle diameter of the ITO nanoparticles on the transparency and the surface resistance of the ITO thin films were measured. As the average particle diameter increased, the transparency and the surface resistance decreased from 92 to 83% and from 1.0 × 10⁴ to 0.8 × 10⁴Ω/□, respectively.     

High-sensitivity microwave detector based on a Josephson heterostructure

The possibility of using the Josephson heterostructure composed of a nanoscale metallic absorber separated from superconducting strips by thin insulating layers as a high-sensitivity microwave detector has been considered theoretically. The inductive response of such a detector has been calculated and the influence of the nonequilibrium of the electron subsystem of the metallic absorber on its response has been analyzed. The limiting sensitivity of the proposed detector has been found.     

Thermal oxidation-grown vanadium dioxide thin films on FTO (Fluorine-doped tin oxide) substrates

By deposition of metallic vanadium on FTO substrate in Argon atmosphere at room temperature, the sample was then annealed in furnace for 2 h at the temperature of 410 °C in air ambient. (1 1 0) -orientated vanadium dioxide films were prepared on the FTO surface. A maximum transmittance of ∼40% happened at 900–1250 nm region at room temperature. The change of optical transmittance at this region was ∼25% between semiconducting and metallic states. In particular, vanadium dioxide thin films on FTO exhibit semiconductor–metal phase transition at ∼51 °C, the width of the hysteresis loop is ∼8 °C.     

Sonochemical syntheses of a nano-sized copper(II) supramolecule as a precursor for the synthesis of copper(II) oxide nanoparticles

Nanoparticles of a three-dimensional supramolecular, [Cu(L)₂(H₂O)₂] (1), (L⁻ = 1H-1,2,4-triazole-3-carboxylate), have been synthesized by a sonochemical process and characterized by scanning electron microscopy, X-ray powder diffraction, IR spectroscopy and elemental analyses. The thermal stability of compound 1 both its bulk and nano-size has been studied by thermal gravimetric (TG) and differential thermal analyses (DTA) and compared each other. Concentration of initial reagents effects on size and morphology of nano-structured compound 1, have been studied. Calcination of the nano-sized compound 1 at 600 °C under air atmosphere yields CuO nanoparticles.     

Studies on the electrochemiluminescent behavior of luminol on indium tin oxide (ITO) glass

The electrochemiluminescence (ECL) of luminol on indium tin oxide (ITO) glass was high even under a low potential around 0.4-0.5 V, which was quite different from other electrodes such as platinum. ITO nanoparticles were synthesized and used in the research on ITO glass in the ECL process. A static interaction between ITO and luminol is confirmed from UV-vis and fluorescence spectra. Then the ECL enhancement can be supposed to originate from the adsorption of luminol on ITO, which facilitated luminol’s oxidization to the excited state, giving out ECL. On the other hand, ITO can catalyze the generation of reactive oxygen species (ROSs), similar to some other nanomaterials, which also favored the ECL enhancement of luminol.     

Hologram recording in cadmium and copper doped cadmium sulphide

Photoinduced changes in the optical absorption of large crystals of cadmium sulphide doped with cadmium and copper, are used to store Bragg-angle holograms by means of a He-Ne laser. The recordings are stable in the dark at room temperature and can be erased either optically or thermally. Diffraction efficiencies of over 1% at a write energy of about 1J/cm² are obtained.     

Optical fiber refractometers based on indium tin oxide coatings fabricated by sputtering

This Letter presents the fabrication of optical fiber refractometers based on indium tin oxide (ITO) coatings deposited by sputtering with response in the visible region. ITO thin films have been sputtered by means of a rotating mechanism that enables the fabrication of smooth and homogeneous coatings onto the optical fiber core. The ITO coating acts as a resonance supporting layer. This permits us to couple light from the waveguide to the ITO-coating/external medium region at specific wavelength ranges. The device is sensitive to external medium refractive index, which allows its utilization as a refractometer. The sensitivity is dependent on the coating thickness, ranging from 523.21 to 1221 nm/refractive index unit in the explored sensors. The sensor development process is time effective compared to other techniques such as dip coating or layer-by-layer self-assembly, which is interesting in terms of mass production.     

Synthesis of nano-sized antimony-doped tin oxide (ATO) particles using a DC arc plasma jet

Nano-sized antimony-doped tin oxide (ATO) particles were synthesized using DC arc plasma jet. The precursors SnCl₄ and SbCl₅ were injected into the plasma flame in the vapor phase. ATO powder could conveniently be synthesized without any other post-treatment in this study. To control the doping amount of antimony in the ATO particles, the Sb/Sn molar ratio was used as an operating variable. To study the effect of carrier gas on the particle size, argon and oxygen gases were used. The results of XRD and TGA show that all Sb ions penetrated the SnO₂ lattice to substitute Sn ions. With the increased SbCl₅ concentration in source material, the Sb doping level was also increased. The size of the particles synthesized using the argon carrier gas was much smaller than that of the particles prepared using the oxygen carrier gas. For the argon gas, PSA results and SEM images reveal that the average particle size was 19 nm. However, for the oxygen gas, the average particle size was 31 nm.     

Fast diffusion of copper(I) ions in NaI

Results are presented for nmr investigations into the diffusion of Cu⁺ in NaI. The nmr results show that a considerable amount of the copper(I) ions is incorporated interstitially and that the mean jump frequency ν_Cu of the Cu⁺ ions is much higher than that of the host cations: ν_Cu/ν_Na ≈ 820 at 320 °C. Two values for the temperature dependence of ν_Cu are found: E₁ = 1.63 eV (T < 300 °C) and E₂ = 0.61 eV (T > 300 °C). The nature of the mechanism of the Cu⁺-migration in NaI is discussed and a model proposed. The interstitial incorporation and fast diffusion of the Cu⁺ ions is confirmed by a comparison with the results for CdI₂ doped NaI. CdI₂ is incorporated substitutionally and the mean jump frequency ν_Cd is lower than that of the host ions: ν_Cd < 10⁸ s^-1 at 650 °C.For the pure substance conductivity measurements were performed too, for vomparison. The agreement of nmr and conductivity data is good. From both δH_m = 0.59 eV and δH_s = 2.08 eV were calculated in excellent agreement with recently reported data. It is shown that the presence of oxygen in the samples leads to wrong data. A method for removing this impurity is described.