Now showing items 1-10 of 31
Infrared activity in the Aurivillius layered ferroelectric SrBi2Ta2O9
(American Physical Society, 1998-03-01)
Experimental studies were carried out on infrared-active phonons in the Aurivillius ferroelectric SrBi2Ta2O9 (SBT), using reflectivity measurements (down to 200 cm(-1)) and transmission measurements (down to 100 cm(-1)) ...
First-principles study of several hypothetical silica framework structures
(American Physical Society, 1995-09-15)
Several hypothetical silica structures have been generated using a simulated-annealing strategy with an ab initio based covalent-bonding potential. First-principles total-energy pseudopotential methods have been used to ...
Photogeneration and recombination processes of neutral and charged excitations in films of a ladder-type poly(para-phenylene)
(American Physical Society, 1999-08-15)
We introduce a version of the cw photomodulation technique, measured far from the steady state, for obtaining the quantum efficiency, eta, of long-lived photoexcitations in pi-conjugated polymers. We apply this technique ...
ACD estimation of the S-parameter revisited
(Elsevier Science Bv, 1997-05-29)
Systematic scaling in the low-energy excitations of the t-J model in one and two dimensions
(American Physical Society, 1997-05-01)
We present an exact diagonalization study of the low-energy singlet and triplet states for both the one-dimensional (1D) and 2D t-J models. A scan of the parameter ratio J/t shows that for most low-energy states in both ...
Predictions of m(b)/m(tau) and m(t) in an asymptotically nonfree theory
(Amer Physical Soc, 1997-08-01)
Measurement of the spectral momentum distribution of valence-electrons in amorphous-carbon by (e, 2e) spectroscopy
(American Physical Society, 1994-01-15)
The spectral momentum density of the valence band of are evaporated amorphous carbon has been measured by (e, 2e) spectroscopy with significantly improved energy resolution relative to earlier studies. The valence band has ...
Critical dynamics at incommensurate phase transitions and NMR relaxation experiments
(Amer Physical Soc, 1999-05-01)
We study the critical dynamics of crystals which undergo a second-order phase transition from a high-temperature normal phase to a structurally incommensurate (IC) modulated phase. We give a comprehensive description of ...
Origin of scintillation in cerium_doped oxide crystals
(AIP Publishing, 1995-05)
We propose here a model of the scintillation from complex oxide single crystalsdoped with Ce3+ ions to explain the correlation observed between scintillation light yield and intrinsic luminescence of the matrix.
Crossover From Self-Similar to Self-Affine Structures in Precolation
(Editions Physique, 1994-05-20)
We study the crossover from self-similar scaling behavior to asymptotically self-affine (anisotropic) structures. As an example, we consider bond percolation with one preferred direction. Our theory is based on a ...