A combined experimental and first principles study of Cu defects in bulk ZnO is presented. Cu particles are epitaxially deposited on the polar O-ZnO(0001) surface at room temperature. Upon heating, a broadening of the quasielastic peak in high resolution electron energy loss spectra is observed, corresponding to an electronic doping effect of Cu atoms in bulk ZnO with an ionization energy of 88...

The effect of lateral pressure on the wavelength response characteristics of a fiber Bragg grating embedded in a cylindrical package of silicone rubber has been investigated in this report. Due to high Poisson’s ratio (0.48) and low stiffness of silicone rubber, force applied in one direction will be efficiently transferred to the perpendicular direction also. A wavelength shift of more than 1 ...

The Sound attenuation and dispersion in saturated gas-vapor-droplet mixture in the presence of evaporation has been investigated theoretically. The theory is based on an extension of the work of Davidson (1975) to accommodate the effects of nonlinear particle relaxation processes of mass, momentum and energy transfer on sound attenuation and dispersion. The results indicate the existence of a s...

We report the analysis and characterization of natural and modified oligonucleotides by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The present technology was highly improved for this class of compounds by using a new matrix, 2,4,6-trihydroxy acetophenone, together with di- and triammonium salts of organic or inorganic acids to suppress peak broa...

We have studied the quasi-two-dimensional exciton in ZnSe/ZnxMg12xSySe12y ~x50.85, y50.21! single quantum wells ~SQWs! by photoluminescence and photoluminescence excitation spectroscopy. Self-consistent calculations of the peak energies for a series of SQWs give the conduction band discontinuity DEc50.40DEg and the binding energy of the n51 heavy-hole exciton Eb~hh1!522.1 meV for an 8 nm well w...

Density functional theory calculations together with highly resolved gas-phase ultraviolet photoelectron spectroscopy have been applied to oligothiophene chains with up to eight thiophene rings. One of the important parameters governing the charge transport properties in the condensed phase is the amount of energy relaxation upon ionization. Here, we investigate the impact on this parameter of ...

We have prepared a series of trialkylsilylethynylated anthracenes (a–d) to investigate the effects of solid-state interactions and acene substitution on the electroluminescence spectra of OLED devices. We designed these materials to have differing amounts of -face interactions and various film morphologies. We were particularly interested in intermolecular interactions between aromatic faces, w...

Numerous experiments have shown that strain broadening caused by dislocations can be well described by a special logarithmic series expansion of the Fourier coefficients of Bragg reflection peak profiles. In the present work it will be shown that this formalism can be incorporated into the classical methods of Williamson-Hall and Warren-Averbach. The new procedures are suggested to be called mo...

Author(s) of this paper may load this reprint on their own web site provided that this cover page is retained. Republication of this article or its storage in electronic databases or the like is not permitted without prior permission in writing from the IUCr. The problem of asymmetric X-ray diffraction peak broadening caused by dislocations is investigated. The leading term responsible for the ...

Bismuth telluride (Bi2Te3) nano particles were prepared by refluxing method in different conditions such as varying concentration of KOH and reaction timings. X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements have been performed for structural and phase formation studies. The nanoparticles are showing the same structure of bulk except broadening of peak confirmed b...