Materials Literature
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This graduate textbook presents a concrete and up-to-date introduction to the theory of Coxeter groups. The book is self-contained, making it suitable either for courses and seminars or for self-study. The first part is devoted to establishing concrete examples. Finite reflection groups acting on Euclidean spaces are…
The optical absorption and electron spin resonance spectra of vanadyl-and copper-doped rubidium cadmium sulphate hexahydrate are investigated at room and liquid nitrogen temperatures. From the analysis, the spectra are ascribed C 4v site symmetry in the case of VO 2+ ions and D 2h site symmetry in the case of Cu 2+ io…
Solid solutions of (KI${)}_{1\mathrm{\ensuremath{-}}\mathit{x}}$(${\mathrm{NH}}_{4}$I${)}_{\mathit{x}}$ with concentrations x=0.14, 0.43, and 1 were investigated using dielectric spectroscopy. The high-temperature rocksalt structure of these compounds exhibits a dipole moment of 1.4 D. For x=0.14 and 0.43 the NaCl str…
The magneto-optical polar Kerr effect has been measured on CuCr2Se4 single crystals between 0.55 and 5.0 eV. The single Kerr ellipticity εK reaches −1.19° at 0.96 eV which is (besides PtMnSb with θK=−1.27° at 1.72 eV) the highest value ever observed at room temperature. The figure of merit R1/2(θ2K + ε2K)1/2 has a max…
The temperature dependence of the infrared-active internal modes of NaNO 3 has been investigated between 77 K and 700 K. The structural phase transition at 549 K is observed through the appearance of additional peaks subsidiary to the expected nitrate group internal modes. In particular, an extra peak is observed at s…
The authors present novel real-space renormalization results for a lattice model of the collapse (coil-globule) transition of a polymer molecule adsorbing to a wall. These results support the conjecture that adsorption stabilises the collapsed phase by enhancing the collapse transition temperature. The analysis is dev…
A molecular-dynamics simulation is carried out to study the changes in statistical geometry and related dynamical properties in the Li2SiO3 system at the glass transition point. The number of oxygens around each cation within the first coordination shell is taken as the number V of vertices of the polyhedron that char…
The complete nucleotide sequence of the Clostridium thermoaceticum formyltetrahydrofolate synthetase (FTHFS) was determined and the primary structure of the protein predicted. The gene was 1680 nucleotides long, encoding a protein of 559 amino acid residues with a calculated subunit molecular weight of 59,983. The ini…
High-speed laser direct writing of tungsten conductors using tungsten-hexacarbonyl [W(CO)6] is demonstrated. Tungsten lines were constructed on the Si-LSI substrate at a writing speed as high as 300 μm/s with laser-induced low-pressure chemical vapor deposition. This speed is more than two orders of magnitude higher t…
The response of a growing crystalline dendrite to a brief localized heat pulse applied near its tip was investigated in a directional solidification experiment on succinonitrile containing 1% acetone. The induced deformation was initially unobservably small, but grew rapidly into a sidebranchlike feature with time. Th…
The authors present a comparative study of the properties of two solution-processible alkyl-substituted polythienylenes, poly(3-hexyl thienylene), P3HT and poly(3-dodecyl thienylene), P3DT. Both show the onset of pi - pi * interband absorption at 2 eV with the peak in absorption coefficient near 2.5 eV, and both show…
The first measurements are reported for the AC conductivity (real and imaginary parts) of the semiconducting CuO-Bi 2 O 3 -P 2 O 5 glasses in the frequency range 10 2 -10 5 Hz and in the temperature range 80-4000 K. The experimental results have been analysed in the light of various theoretical models proposed for amo…
The structures of 2H PbI 2 , grown from a gel, and of 4H PbI 2 , obtained by thermal transformation of 2H at 423 K, have been determined by single-crystal X-ray analysis. The space groups are P3m1 for 2H and P3m1 for 4H. The occupancy of the atomic sites in the 2H and 4H structures is only about 80-85%, indicated by a…
Photoluminescence and cathodoluminescence are studied in MgO and CaO stabilized ZrO2 crystals before and after mechanical damage by grinding and Vickers indentations. Significative differences in the emission and excitation spectra are found between crystals stabilized by MgO and CaO. Mechanical damage in cubic stabil…
The hardness of materials, H, is dependent on grain diameter, d, in a similar way as the flow stress in the Hall-Petch relation: H = Ho + KHd−1/2, where, Ho and KH are constants. The microhardness of 2S-Al (99.5% Al), pure Cu, Al-MD 105 (Al-1% Al2O3), and Duralumin (Al-3.94% Cu) is found to vary with grain size accord…
For KH 2 PO 4 (KDP) and NH 4 H 2 PO 4 (ADP), the orientation of the optical indicatrix for NaD light (589 nm) has been determined in the low temperature orthorhombic phase, through the optical and X-ray measurements. For both KDP and ADP, the principal refractive indices, n a , n b and n c have been found to satisfy n…
[YC12(H20)6]C1, Mr = 303.356, monoclinic, P2/n, a = 7.8346 (25), b = 6.4729 (26), c = 9.5817 (50) angstroms, beta = 93.768 (35) °, V = 484.86 cubic angstroms, Z = 2, Dx = 2.0776 g cm -3, Mo Kalpha (A = 0.71069 angstroms),/z = 68.66 cm- 1, F(000) = 300, room temperature, final R = 0.0449 for 940 unique observed reflexi…
The spatial and temporal evolution of photodarkening in chalcogenide glasses is simulated by a simple kinetic model and tested against experiments. In the model, photodarkening, a gradual decrease of the energy of the absorption edge caused by above-band-gap illumination, is the additional absorption at defects create…
The anions of (TMTSF) 2 ClO 4 order below about 24 K. The speed at which this transition is passed has a drastic influence on the low temperature electronic properties of this salt. We determined as a function of the cooling rate the number of ordered ClO 4 as well as the average size of the ordered domains. A high re…
The phase transition sequence of a K 2 ZnBr 4 crystal was investigated by DTA and dielectric measurements. It was found that the crystal undergoes at least two phase transitions, at -118°C and around 200°C, on heating. Ferroelectricity was observed below the lower transition point.