Amorphous carbon thin films containing 0–50 at. % Cu have been grown by mass selected ion beam deposition in order to synthesize isolated Cu nanoparticles within a diamond-like matrix. Raman spectroscopy and x-ray photoelectron spectroscopy show that the sp3 content of the matrix decreases with increasing Cu content. Simultaneously, the mean particle size of the embedded Cu nanocrystals increases, as x-ray diffraction and transmission electron microscopy analysis reveal. There is apparently no dependence of the matrix structure on the Cu+ ion energy, while the Cu content is strongly influenced by this deposition parameter.
Below its ordering temperature at 105 K, perovskite-type SrTiO(3) exhibits a tetragonal phase with three different structural domains that are strongly influenced by the application of uniaxial mechanical stresses and electric fields. A careful neutron diffraction study of superlattice reflections provides full quantitative information about the varying domain distributions under external loads as a function of temperature. It is shown that electric field and uniaxial stress exhibit competitive effects and the simultaneous application leads to a complex redistribution behaviour of the tetragonal domains. The results are discussed in the context of the formation of a field induced ferroelectric phase at low temperatures. The experimental findings demonstrate that its polarization is always perpendicular to the tetragonal axis and the polar phase has orthorhombic symmetry.
Using small angle neutron scattering in combination with optical Raman spectroscopy, phase transitions in the micellar system tetradecyl-trimethylammonium bromide (TTAB) have been investigated in a wide range of temperatures, pressures and surfactant concentrations. Allowing for the sluggish kinetics of crystallisation, the phase diagram in the p-T-c space could be determined that is dominated by a pronounced two-phase region of coexisting liquid and solid phases at elevated pressures.
No periodate oxidation on chitin? For the first time, direct selective alkaline periodate oxidation of chitin led to the isolation of ordered domains as uniform anisotropic and zwitterionic ChNCs after simultaneous removal of non-ordered domains.
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