Materials Literature
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Quantitative phase analysis of multicomponent mixtures using X-ray powder diffraction data has been approached with a modified version of the Rietveld computer program of Wiles & Young [J. Appl. Cryst. (1981), 14, 149–151]. This new method does not require measurement of calibration data nor the use of an internal sta…
The field of thermoelectric energy conversion is reviewed from both a theoretical and an experimental standpoint. The basic theory is introduced and the thermodynamic and solid state views are compared. An overview of the development of thermoelectric materials is presented with particular emphasis being placed on the…
A systematic account is given of the methods of preparation of oxide sulphides having the composition Ln2O2S (where Ln = lanthanide, Sc, or Y) in the form of polycrystalline materials, single crystals, thin films, and ceramics. The crystal-chemical, thermal, thermodynamic properties of the oxide sulphides are consider…
Progress in the Understanding of Ceramic Microstructures and Interfaces since 1976.- Ceramic Microstructures: The Art of the Possible.- Designing Material Structures.- Purposive Design of Nanocomposites: Entire Class of New Materials.- Design of High Thermal Expansion Glass-Ceramics Through Micros truetura1 Control.-…
The fundamental concepts of the homotopy theory of defects in liquid crystals and the results of experimental studies in this field are presented. The concepts of degeneracy space, homotopy groups, and topological charge, which are used for classifying the topologically stable inhomogeneous distributions in different…
A complex phase transition sequence was found in (C 3 H 7 NH 3 ) 2 CuCl 4 crystals. The specific heat C p , thermal expansion Delta d/d 0 and linear birefringence Delta b have been used to study this sequence. By comparison with the isomorphous manganese compound, two unusual features can be identified: a re-entrant p…
A general model for heat conduction in dielectric solids (at low temperatures) is elaborated that meets the restrictions placed on it by thermodynamics. The model is also shown to fit experimental data on second-sound speeds which, in turn, bear evidence of the need for a thermal inertia. Furthermore, the experimental…
The transient optical absorption and luminescence induced by irradiation of amorphous SiO 2 with an electron pulse have been measured. It is found that the transient optical absorption spectra do not depend on impurities and have a strong peak at 5.3 eV and a satellite peak at 4.2 eV. The peak energy of the luminescen…
We describe a novel technique for the fabrication of electro-optic (EO) waveguides in integrated optic device structures employing organic EO materials. The technique combines the poling and waveguide formation steps by utilizing patterned poling electrodes and the induced birefringence associated with the poling proc…
The temperature dependence of the inelastic neutron-scattering intensity from vitreous silica has been studied between 50 and 300 K down to frequencies of 150 GHz. Above 500 GHz one finds essentially harmonic behavior. Low-frequency anharmonic behavior can be described by a relaxational model using parameters determin…
Room-temperature vibronic pulsed laser action in trivalent chromium-activated forsterite (Cr3+:Mg2SiO4) is reported for the first time. The free-running laser emission is centered at 1235 nm of the broad 4T2→4A2 fluorescence band, and has a bandwidth of ∼22 nm.
ABSTRACT In this paper a mathematical model simulating the kinetics of silica dissolution and hydroxyl ion consumption in a typical alkaline flooding environment is developed. The model is based on the premise that dissolution occurs via hydrolysis of active sites through the formation of an intermediate complex, whic…
Abstract The new austenitic alloy N08367 (AL-6XN®) was developed as an extension of the familiar N08366 (AL-6X™) alloy which has been in service primarily as condenser tubing in seawater-cooled heat exchangers for times approaching 15 years. There are close to 9 million meters (30 million feet) of thin-walled condense…
Abstract Microbial induced corrosion (MIC) relevant to nuclear power plant systems is reviewed. The long construction times associated with nuclear plants and the large number of redundant or standby systems where water is allowed to remain stagnant for long periods of time produce conditions under which MIC can occur…
Most previous articles on microbiologically influenced corrosion (MIC) failures describe individual failures but do not compare them. This study compares three factors, microstructure of welds, ferrite content and sensitization. Twelve austenitic stainless steel welds with reported pitting corrosion were examined. Ele…
It is suggested that the ``supermodulus effect'' observed for composition-modulated superlattices arises from the presence of the structurally disordered solid interfaces and not necessarily from electronic structure effects.
The crystal structure of (CH 3 ) 4 NNO 3 at 303 K is tetragonal (D 4h 7 (P4/nmm)) with Z=2 and the nitrate ions are disordered. Differential scanning calorimetry data revealed the phase sequence. The Raman and infrared spectra (10-5000 cm -1 ) of single crystals and polycrystalline samples of (CH 3 ) 4 NNO 3 were inve…
The additive coloration of potassium halide powders is reported. The optimum coloration temperature decreases with decreasing particle size. The stability of coloration was profoundly reduced in the powders in comparison with that in single crystals. The reduced stability of coloration is interpreted as due to the int…
Several transition metal compounds show a transition from the low-spin (LS) to the high-spin (HS) electronic state with increasing temperature. The cooperative nature of the transition is usually parametrised by an interaction constant Gamma , the origin of which is still under discussion. In the frame of the lattice…
Vibrational absorption spectra in the infrared, and vibronic absorption and luminescence bands in the visible and ultraviolet spectral regions have been studied for synthetic diamonds grown using 99% 13 C. This is the first such study of any semiconductor for which the isotope of the host material has been totally cha…