Materials Literature
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The c-axis resistivity of highly oriented pyrolytic graphite has been measured from 2 to 300 K under hydrostatic pressures of up to 40 kbar. A resistivity peak near 40 K, typical for this type of graphite at ambient pressure, rapidly diminishes with increasing pressure but does not shift its position with respect to t…
Optical reflection and absorption spectra of SrTe and BaTe have been measured in the pressure range of 0 to 400 kbar at 300 K. Excitonic transitions related to the lowest direct gap in the rocksalt (B1) structure shift to lower energy with increasing pressure and are attributed to a Te 5p to Ba 5d (Sr 4d) transition a…
The effects of the local dielectric environment on the surface-plasmon resonances of annealed metal-island films are studied experimentally and modeled theoretically. Silver-island films were annealed to produce spheroidal shaped particles which exhibit well-resolved resonances in polarized, angle-resolved, absorption…
An interpretation model for low reflectivity in ultrahigh spatial-frequency holographic relief gratings is proposed. The model is based on the concept that the grating effective index, caused by grating ultrahigh spatial frequency, is graded in the depth direction and forms an antireflective constitution similar to th…
The proton spin lattice relaxation rate (1 / T 1 ) in the superconducting state of(TMTSF) 2 ClO 4 has been measured at zero magnetic field using the field cycling technique. It was found that the enhancement of 1 / T 1 just below T c , commonly observed in typical BCS superconductors, was absent and 1 / T 1 varied as…
Near-edge x-ray-absorption fine-structure studies of ${\mathrm{O}}_{2}$ chemisorbed on Ag(110) and Pt(111) surfaces near 100 K reveal different predissociation stages of molecular oxygen. ${\mathrm{O}}_{2}$ on Ag(110) exhibits only a ${\ensuremath{\sigma}}^{\mathrm{*}}$ resonance and resembles a single-bonded peroxo s…
We have measured the thermal conductivity of polymethylmethacrylate (PMMA), amorphous ${\mathrm{As}}_{2}$${\mathrm{S}}_{3}$, Ca-K nitrate glass, three ${\mathrm{SiO}}_{2}$-based glasses, and glycerol in the temperature range 30--300 K, using an ac technique that eliminates errors from blackbody radiation. This techniq…
It is shown how the results of low-temperature electrical and thermal conductivity measurements may be used to characterise and determine the defect structure of pristine and intercalated carbon fibres of various origins.
The aromatic (A) and quinoid (Q) forms of polythiophene (PT) have entirely different energy gaps: ∼0.5 eV for the quinoid form and ∼2 eV for the aromatic form, respectively. The energy gaps and stability of derivatives of PT are studied by total MNDO geometry optimization using energy band theory for the total energy…
The discrete scale invariance of quasi-periodic systems leads to a scaling relationship Omega =L -z f(L) between a characteristic dynamic variable Omega and length L, where f(L) is a periodic function of ln L. The dynamic exponent z can be calculated for diffusion, spin wave and phonon dynamics (where Omega is respect…
Radiation effects of X-rays in zircon (ZrSiO 4 ) single crystals were studied at RT, by analysing the kinetics and spectrum of the thermoluminescence between 20 degrees and 420 degrees C. The results indicate that some of the electrons produced by the irradiation are captured by Dy 3+ impurities apparently substitutin…
A 2D Ni-Cr quasicrystal displaying a twelvefold symmetry consists of a dodecagonal quasiunit cell (QUC) which is an intergrowth of ${\mathrm{Zr}}_{4}$${\mathrm{Al}}_{3}$ and ${\mathrm{Cr}}_{3}$Si structures. If the QUC is represented by a geometric point, then this quasicrystal can be described by a quasilattice deriv…
Abstract This paper is a review of leading research in the field of bacterial corrosion monitoring with specific emphasis on systems that transport liquids rather than gases. However, the principles of bacterial corrosion presented below are universal and independent of whatever media is transported through the pipeli…
The phase separation of a binary liquid mixture contained in a rigid porous medium has been investigated by study of the light scattered at 90\ifmmode^\circ\else\textdegree\fi{} from a porous glass rod containing a critical mixture of n-${\mathrm{C}}_{6}$${\mathrm{H}}_{14}$+n-${\mathrm{O}}_{6}$${\mathrm{F}}_{14}$. Evi…
Abstract Accelerated corrosion experienced in the overhead system of an atmospheric crude distillation column has been analyzed to determine the cause of the corrosion occurring at temperatures above the aqueous dew point. Results of field monitoring tests, laboratory tests and thermodynamic considerations all confirm…
A new nonlinear optical crystal 2-cyclooctylamino-5-nitropyridine (COANP) with point group symmetry mm2 has been grown by a temperature difference solution growth technique. Its linear and nonlinear optical properties have been investigated. The refractive indices na =1.702, nb =1.847, and nc =1.681 (λ=550 nm) and the…
A new series of hepta-coordinated mixed-ligand cyanonitrosyl complexes of vanadium (having {VNO}4 electron configuration1), formed by the interaction of potassium hexa-cyanonitrosylvanadate(I) monohydrate with some heterocyclic organic bases like 2, 3-, 2, 4-, 2, 6- and 3, 5- lutidines, 2, 3, 6- and 2, 4, 6- collidine…
The Fresnel coefficients describing reflection and refraction at an interface are derived in terms of the elements of the characteristic admittance matrix of an anisotropic medium. The cases considered include the general gyroelectromagnetic medium under normal incidence and the polar and longitudinal orientations und…
Abstract Small‐ and intermediate‐angle (0.006 < Q < 0.25 Å) neutron scattering experiments have been performed on polyethylene terephthalate (PET). Amorphous and semicrystalline samples with deuterated PET molecular weights of 24,200 and 40,500 were prepared. The average value of R /M determined in the small‐ang…
A light-pipe technique has been used to measure infrared spectra of U0 2 , U 3 O 8 , and UO 3 , in the range 2000 to 450 cm −1 . Comparison with transmission spectra found in the literature indicates that the technique is very suitable for characterization of actinide powders and will therefore be a useful tool for fu…