Materials Literature
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We investigate correlations between the atomic-scale structure and the global electronic and vibrational properties in amorphous carbon versus mass density. The model structures have been generated by applying different annealing regimes using a density-functional-based nonorthogonal tight-binding molecular dynamics.…
By the use of ultraviolet laser pulses of microsecond and millisecond duration it is shown that the chemistry of the transformations of Kapton by UV laser radiation is strongly dependent on the intensity (power/unit area) of the laser beam. With these long pulses, the polymer was not ablated. The decomposition resulte…
59 Co and 139 La NMR measurements have been performed to study the microscopic magnetic properties closely related with the spin state of a trivalent cobalt ion in LaCoO 3 . The temperature-independent 59 Co and 139 La Knight shifts below ∼ 30 K clearly revealed the presence of a nonmagnetic ground state at low temper…
Film stability and structure formation inside a liquid film containing colloidal particles are investigated by Monte Carlo (MC) numerical simulations and by analytical methods. The effective pair interaction between particles is calculated from the Ornstein–Zernike theory with Percus–Yevick closure. Consistent with th…
Using the tight binding molecular dynamics method (TBMD), the structural and dynamical properties of graphitic tubules are studied. The phonon dispersion and density of states of graphitic tubules with various helicities and diameters are calculated. Phonon modes in tubules are softened by the curvature when compared…
X-ray diffraction experiments have been performed near the ferroelastic first-order phase transition temperature in lanthanum niobate LaNbO 4 , which transforms from a tetragonal phase to a monoclinic phase at T c =768 K with a discontinuous change of the lattice parameter Δβ=0.4° . With regard to the temperature depe…
A semiempirical model of the Seebeck coefficient for a small polaron hopping conductor is presented. The population of small polarons is allowed to change as a function of temperature via the mechanism of charge disproportionation. The energy required for polaron formation by the disproportionation mechanism is modele…
PbO is a layer compound which exists in two polymorphic forms, a red tetragonal (\ensuremath{\alpha}) and a yellow orthorhombic (\ensuremath{\beta}) modification. Ab initio band-structure calculations are presented for both phases. The calculated energy gaps are in agreement with optical data. The band-structure calcu…
Measurements of galvanomagnetic effects in the temperature range 4.2--300 K and photoinduced ``transient thermoelectric effect'' (TTE) along the ${\mathit{C}}_{2}$ axis at 300 K have been made for two types of solid solutions of semiconductors ${\mathrm{Sb}}_{2\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{In}}_{\mathit…
We analyze optical-absorption and Raman-scattering measurements of CdS- and Zn-doped borosilicate glass, heat treated at 600 \ifmmode^\circ\else\textdegree\fi{}C to 725 \ifmmode^\circ\else\textdegree\fi{}C, to study the nucleation and growth of II-VI nanoparticles. The energy of vibrational Raman modes indicates that…
The thermopower η of Sr1−xLaxTiO3 ceramics was investigated up to x=0.5 and in the temperature range between 150 K and 1200 K. In addition, the carrier concentration n was determined by Hall measurements and by a chemical Ti3+-analysis. For low temperatures and high n, η depends linearly on temperature and on n−2/3, a…
The ab initio pseudopotential method within the local-density approximation and the quasiparticle approach have been used to investigate the electronic excitation properties of hexagonal (6H, 4H, 2H) and zinc-blende (3C) silicon carbide. The quasiparticle shifts added to the density-functional eigenvalues are calculat…
The laser-induced crystallization behavior of GeTe-based amorphous alloys has been measured with a novel multipulse laser technique. This enables the composition dependence of the nucleation rate and crystal growth speed to be independently followed. Two types of crystallization are investigated. The first involves si…
The notion and usefulness of the effective dielectric constant in silicon nanocrystallites are analyzed using a self-consistent linear screening calculation of hydrogenic impurities. It is shown that the self-consistent screened potential induced by the defects can be reasonably approximated by the classical electrost…
The 2\ifmmode\times\else\texttimes\fi{}1/1\ifmmode\times\else\texttimes\fi{}2 surface reconstruction of a homoepitaxial diamond (001) surface has been examined using a scanning tunneling microscope at an atomic scale and reflection electron microscopy at a macroscopic scale. The monohydride dimer, which is a unit of t…
We apply a previously reported density-functional-based scheme for the construction of common nonorthogonal tight-binding (TB) matrix elements for Si and SiH within the framework of the linear combination of atomic orbitals formalism using the local-density approximation. By only considering two-center integrals the H…
Transient and persistent holographic gratings have been observed in dye- and fullerene C(60)-doped nematic liquid-crystal films. The nature and time evolution of the underlying mechanisms, such as space-charge field production, flows, and dielectric- and conductivity-induced torques, and the resultant director axis re…
Research Article| October 15 1995 Structure and function of the aromatic amino acid hydroxylases S E Hufton; S E Hufton 1Olive Miller Protein Chemistry Laboratory, Murdoch Institute, Royal Children′s Hospital, Parkville, Victoria 3052, Australia Search for other works by this author on: This Site PubMed Google Scholar…
Magnetotransport properties were investigated for a crystal of perovskite-type manganese oxide, Pr 1- x Ca x MnO 3 ( x =0.3). The single-crystal compound is insulating and below 220 K shows the charge-ordering of Mn 3+ and Mn 4+ species. Application of a magnetic field (>20 kOe) changes a canted antiferromagnetic insu…
We have recently reported that bound electron-hole pairs (Mott-Wannier excitons) are the dominant source of photoelectron emission from specially prepared [``as-polished'' C(111)-(1\ifmmode\times\else\texttimes\fi{}1):H] negative-electron-affinity diamond surfaces for near-band-gap excitation up to 0.5 eV above thresh…