Materials Literature
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[CoNd 2 (μ-C 2 H 3 O 2 ) 8 (H 2 O) 10 ] cristallise dans P1 avec a=8,243, b=10,368, c=11,497 A, α=111,64, β=107,94, γ=93,45 o , Z=1; affinement jusqu'a R=0,024. Les chaines sont construites de prismes rhomboedriques deformes [NdO 7 (OH 2 ) 2 ], chapeautes sur 3 faces, et d'octaedres CoO 6 presque reguliers
Elastic-neutron-scattering experiments, performed on a single crystal of ${\mathrm{Tl}}_{0.3}$${\mathrm{MoO}}_{3}$, show the formation of a periodic distortion below the metal-semiconductor transition at about 170 K. Similar to the isostructural blue bronzes ${\mathrm{K}}_{0.3}$${\mathrm{MoO}}_{3}$ and ${\mathrm{Rb}}_…
The kinetics of the amorphous-to-tetragonal transformation has been studied in sol-gel-derived thin films of zirconia deposited on alumina substrates. A rapid-thermal-annealing system was used which allowed good control of processing parameters such as temperature and heating rates. The effect of these two parameters…
Several physical properties of thin plasma-polymerized films have been measured using a new fiber-optic-based technique. Films of plasma-polymerized tetrafluoroethylene (PPTFE) deposited on the end of an optical fiber form an optical cavity, the reflectivity of which is very sensitive to the film thickness. The fiber…
Interest continues to grow in polymers that have inherent biological activity or polymers which are covalently attached to well known drugs. This paper provides an introduction to these types of materials and a general review of the different types of polymeric drugs, polymeric drug conjugates, polymeric prodrugs, and…
We have examined the propagation of acoustic phonons in silicon on the basis of two lattice-dynamics models: a bond-charge model and an effective-force-constant model consisting of only short-range forces. Phonon propagation is governed predominantly by phonon focusing due to elastic anisotropy and elastic scattering…
Films with a composition PbZr0.53Ti0.47O3 were prepared on different platinum bottom electrodes using a spin-coating process followed by metalorganic decomposition. The film morphology and structure were characterized by scanning electron microscopy and x-ray diffraction analysis. The morphology was strongly influence…
We have calculated total and binding energies of zinc-blende-structure boron nitride. Starting from a self-consistent-field ground-state calculation within a finite basis of Gaussian orbitals centered at the different atoms, the electron correlations were treated by applying the local ansatz. The electronic correlatio…
Theoretical modeling of surface-plasmon-enhanced polarization conversion from a diffraction grating is developed. The theory compares very favorably with data. From further modeling it is found that the transverse-magnetic mode to transverse-electric mode available from a metallized grating may approach 100% in approp…
We have performed ab initio calculations of the crystal structure and electronic structure of ${\mathrm{B}}_{6}$O using an expansion in over 11 700 plane waves. The crystal structure is compared with recent x-ray data; contour plots show the two oxygen atoms in the unit cell do not bond to each other, and the heat of…
Low-frequency Raman scattering of amorphous polymers [polyethyleneterephthalate (PET) and polymethylmethacrylate] is investigated. The low-frequency Raman band called ‘‘Boson peak’’ is interpreted in terms of a noncontinuous structure, similar to that of inorganic glasses, i.e., solid amorphous polymers are composed o…
We study the aggregation kinetics of Electro-Rheological Fluid particles which interact through dipoles induced by an external electric field and experience negligible thermal motion. For a system in d-dimensions, our theoretical calculations show that the average cluster size s av increases with time t as s av ∝ t d…
Single-crystal alloys of diamond with Si and Ge are investigated theoretically. An indirect band gap Γv25′ → Δc1 is found for the new semiconductor Si1−x−yGexCy over most compositions x and y, with an indirect Γv25′ → Lc1 gap found for the remaining compositions. The estimated band gaps span the 0.62–5.5-eV-range. Pre…
The dielectric permittivity and loss of vapor-deposited amorphous solid water (ASW) have been measured for fixed frequencies of 1 and 10 kHz from 80 K to its crystallization temperature. Similar measurements have also been made on the cubic ice formed after the crystallization of ASW and the hexagonal ice formed on he…
Second harmonic generation (SHG) has been studied in lithium diborate (Li 2 B 4 O 7 ) single crystal from room temperature up to the melting temperature. The magnitudes of the SHG coefficients d 33 and d 31 , at room temperature are, respectively, 3.1 and 0.4 relative to d 11 of quartz. The decrease of the SHG signal…
The embedded-atom method is used to calculate the surface stresses and the interface stresses for several fcc metals and interfaces between them. While the surface stresses are all positive (i.e., they tend to put the underlying crystal in compression), in several instances (e.g., in the Pt/Ni system) negative interfa…
Perturbation formulas are derived for calculating the vibrational dynamic polarizability (αv) and hyperpolarizabilities (βv and γv ) of polyatomic molecules. These formulas, based on an initial harmonic oscillator approximation, include corrections for mechanical anharmonicity (cubic) terms in the vibrational potentia…
We have performed angle-resolved-photoemission experiments and local-density-functional (LDA) band calculations on NiO to study correlation and band effects of this conceptually important compound. Our experimental result suggests a dual nature of the electronic structure of NiO. On the one hand, the LDA band calculat…
Domain wall contributions to the dielectric, piezoelectric, and elastic properties of tetragonal ferroelectric ceramics, as discussed extensively in the past, are calculated. A simple model shows that the motion of 90° domain walls causes a shear deformation and an approximately homogeneous electric field in the grain…
The full-potential linear-muffin-tin-orbital method in combination with the local-density-functional theory is used to calculate the equilibrium lattice constant, the cohesive energy, the bulk modulus and its pressure derivative, the elastic constants, the Kleinman internal displacement parameter \ensuremath{\zeta} th…