Indium doped zinc oxide nanopowders for transparent conducting coatings on glass substrates

Crystalline indium doped zinc oxide (IZO) nanopowders were synthesized using hydrothermal treatment processing. Increasing the doping ratio of indium in the zinc oxide significantly influences the phase structure and shape of the nanopowders resulting in nanorod to nanoparticulate morphologies. As the doping profile increases, the crystallite size decreases, the band gap energy blue shifts and the specific surface area increases (measured by BET method). Additionally Raman spectroscopy exhibited shifts of several peaks, as well as revealed new peaks, confirming the substitution of indium ions within the zinc oxide lattice sites. An IZO suspension made of IZO nanoparticles (In/Zn = 3 atm.%) with a zeta potential greater than 30 mV at pH = 6 was successfully spin-coated on glass substrates for to make transparent conductive coatings evincing sheet resistances as low as 35 kΩ_□ (ρ = 4.9 × 10^?3 Ω m,) with transmission in the visible range as high as 90 %.     

Enhanced stability of platinized silicon substrates using an unconventional adhesion layer deposited by CSD for high temperature dielectric thin film deposition

Almost all platinized substrates manufactured presently use an TiO₂ adhesion layer to improve the adhesion between the SiO₂ and the Pt. These substrates however are stable till only 800 °C. We show that simply by replacing the TiO₂ with Al₂O₃, the stability of the electrodes can be increased to 1000 °C and more. These substrates can be used for high temperature depositions which standard platinized substrates cannot withstand. Further we show that dielectric thin films of BaTiO₃ and (Ba,Sr)TiO₃ crystallized at higher temperatures show almost a threefold increase in permittivity on these high temperature stable platinized silicon substrates.The large increase in permittivity is attributed to an increase in grain size at high temperatures. PACS 61.82.Fk; 68.35.Np; 68.60.Dv; 77.55.+f; 81.20.Fw     

Dimethylmetall-tropolonate des galliums,indiums und zinns

The reaction of GaMe₃ and InMe₃ (Me = CH₃) with equimolar amounts of α-tropolone forms dimethylgallium tropolonate and dimethylindium tropolonate, respectively, in high yields. Both compounds are monomeric in solution, almost planar 7-/5-ring bicyclic structures of C_2v symmetry can be discussed. According to the X-ray structure determination of Me₂GaTrop (Trop = C₇H₅O₂) this compound is dimeric in the solid state and crystallizes in the monoclinic space group P2₁/c with 4 formula units (2 dimers) per unit cell. Me₂SnTrop₂ is formed by the interaction of Me₂SnCl₂ with LiTrop in a $\text{1}\text{2}$ molar ratio. This ditropolonate is monomeric not only in solution but also in the solid state. The compound crystallizes in the triclinic space group P$\text{1}$ (Z = 4), and the molecules have a cis-structure of approximate C₂-symmetry. The vibrational and NMR spectra of all compounds were measured and are partly assigned.     

Fokker-Planck equation for a periodic potential

The Fokker-Planck equation in one dimension has been solved for a system in a periodic potential and linearly perturbed by a time- and space- varying external electric field. The solution is not exact, but we believe it is less approximate than any attempted previously on this problem. We have calculated the frequency and wave-vector dependent mobility and discussed its behaviour in some limiting cases.The application of our model to various physical situations is discussed.     

Study of a soliton in a medium

The solution of the sine-Gordon equation for a medium is studied in a simplified “quasi-linear” approximation. Several aspects of this approximation are explored and compared with other approximate solutions for the sine-Gordon soliton.     

Generation of fluorescent adducts of malondialdehyde and amino acids: toward an understanding of lipofuscin

Lipofuscin is a yellow-brown, highly fluorescent pigment that undergoes an age-related progressive accumulation in animal cells, mainly in postmitotic cells. It is a heterogeneous, high-molecular weight material associated with proteins, lipids and nucleic acids. Lipofuscin is implicated in many aspects of human health, including aging, oxidative stress, macular degeneration, lipid peroxidation, atherosclerosis, dementia (Alzheimer's Disease) and diseases associated with prions. Although the fluorescent properties of lipofuscin have long been recognized, neither histologists nor chemists have yet isolated the pigments themselves or characterized their optical properties. We have prepared lipofuscinlike species by reacting malondialdehyde (MDA) with cysteine (Cys). MDA:Cys adducts 3:2 and 2:2 are two of those that have been identified among the many that were present in the reaction. Whereas previous attempts to synthesize lipofuscinlike species resulted in compounds that were either nonfluorescent or emitted principally in the blue, the MDA:Cys adducts reported in this study are not only fluorescent but also emit over a broader range.     

Elucidating the structure of surface acid sites on γ-Al2O3

Differential pair distribution function analysis was applied to resolve, with crystallographic detail, the structure of catalytic sites on the surface of nanoscale γ-Al(2)O(3). The structure was determined for a basic probe molecule, monomethylamine (MMA), bound at the minority Lewis acid sites. These active sites were found to be five-coordinate, forming distorted octahedra upon MMA binding. This approach could be applied to study the interaction of molecules at surfaces in dye-sensitized solar cells, nanoparticles, sensors, materials for waste remediation, and catalysts.