Reverse Monte Carlo modeling of amorphous structures in phase-change In0.21Sb0.79 thin film.

The structures of phase-change In(0.21)Sb(0.79) thin film in the amorphous phase were modeled using the reverse Monte Carlo (RMC) method, making simultaneous use of measured x-ray diffraction and x-ray absorption fine structure data. The experimental data that we used do not contain the crystalline phase, which can be observed in the diffraction pattern. Three kinds of initial configurations--a simple cubic lattice, a rhombohedral A7 structure and a dense randomly packed hard sphere form--were used in attempts to reproduce the measured data. The former configuration is thought to be the most probable structure for the crystalline In(0.21)Sb(0.79) thin film. For the latter configuration we could not reproduce the structure of the amorphous In(0.21)Sb(0.79) thin film under the present RMC conditions. We obtained probable structure models for the amorphous In(0.21)Sb(0.79) thin film. We found that the models obtained possess some traces of crystallinity.

Photophysical property and photostability of J-aggregate thin films of thiacyanine dyes prepared by the spin-coating method.

By use of electrostatic interactions of dye molecules and poly(diallyldimethylammonium chloride) (PDDA), the spin-coating technique has been successfully applied to the preparation of stable J-aggregate thin films of thiacarbocyanine dyes on a polycarbonate or quartz plate. The J-aggregate thin films were prepared by the spin-coating of PDDA aqueous solution on dye thin films prepared on a substrate by the spin-coating of 2,2,3,3-tetrafluoro-1-propanol solution of dyes. Photophysical properties of the dye thin films and J-aggregate thin films were studied by measuring the fluorescence spectra, quantum yields, and lifetimes. Coherent size of the J-aggregates was estimated to be 3-12 by means of the absorption bandwidth (full width at half maximum) or radiative lifetime. Photostability of the J-aggregate thin films was also studied in terms of photodegradation efficiency under argon and oxygen in comparison with the dye thin films, and J-aggregate thin films were found to be more stable than the corresponding dye thin films.

Chemical component mapping of pulverized toner by scanning transmission X-ray microscopy.

Toners are micron scale polymer particles constructed of several kinds of resin, pigment, wax, etc. Transmission electron microscopy (TEM) is used for observation of the dispersion of the component materials in toners, but TEM images cannot identify simultaneously all components. Scanning transmission X-ray microscopy (STXM) not only provides simultaneous observation of spatial distributions of wax, resin and carbon black in toners, but it also provides detailed, quantitative, chemical information about the wax and resin environments through chemical component maps derived from multiple energy image sequences. The capabilities of STXM for toner analysis are illustrated by results of a study of a toner for black/white copy/print applications.