Materials Literature
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First-principles molecular dynamics simulations having a duration of 8 ps have been used to study the static, dynamic and electronic properties of l-Ga at the temperatures 702 K and 982 K. The simulations use the density-functional pseudopotential method and the system is maintained on the Born-Oppenheimer surface by…
The magnetocrystalline anisotropy energy $E_{anis}$ for a monolayer of Fe and Ni is determined using a fully convergent tight-binding calculation including $s$-$d$ hybridization. The spin-orbit interaction $λ_{so}$ is treated non-perturbatively. Remarkably, we find $E_{anis}\proptoλ_{so}^2$ and important contributions…
We measured the time dependencies of the dielectric permittivity of a single crystal lead magnoniobate in the zero-field--cooled regime. The logarithmic decay of the dielectric response was observed in the glassy phase. We measured the time $\ensuremath{\tau}$ from the moment of the field application for the phase tra…
We present nonlocal density-functional calculations for a model of the [Fe4S4]3+ cluster found in high potential iron proteins, which consists formally of a ferric pair Fe 3+Fe3+ and a mixed-valence pair Fe 2.5+Fe2.5+. Three Spin Hamiltonian parameters, J (the interlayer Heisenberg interaction), B (a resonance deloca…
We present the results of ab initio calculations on the first-, second-, and third-order molecular polarizabilities of urea. An efficacious general finite field perturbation approach, previously applied in the case of paranitroaniline, is extended to the evaluation of axial and nonaxial components of the nonlinear res…
Mandelate racemase and muconate lactonizing enzyme are structurally homologous but catalyze different reactions, each initiated by proton abstraction from carbon. The structural similarity to mandelate racemase of a previously unidentified gene product was used to deduce its function as a galactonate dehydratase. In t…
We present a simple model for the observed temperature dependence of the thermal conductivity of AlPdMn (Chernikov et al, Phys.Rev.B vol.51, (1995),153). We account for the low temperature data, upto and including the plateau of the thermal conductivity, and discuss the similarities and the differences between the qua…
A model that makes use of the cooperative organization of inorganic and organic molecular species into three dimensionally structured arrays is generalized for the synthesis of nanocomposite materials. In this model, the properties and structure of a system are determined by dynamic interplay among ion-pair inorganic…
The basis of backscatter Kikuchi diffraction crystallographic point-group determination by backscatter Kikuchi diffraction phase identification the atlas of backscattering Kikuchi diffraction patterns: Metals (Nickel, Lead, Tungsten, Iron, Zirconium, Titanium, Cobalt Semiconductors (Silicon, Gallium Arsenide, Gallium…
Abstract Variation of dynamic mechanical propeties like storage modulus ( E′ ) and loss tangent (tan δ) with temperature show the presence of two transitions in the carboxylated nitrile rubber (XNBR) molded in the presence of zinc oxide (ZnO). The low‐temperature transition is due to the glass–rubber transition ( T g…
Abstract A series of a segmented copolymer, poly(4,4′‐dioxy‐2,2′‐dimethyl‐azoxybenzene dodecanedioyl)‐ co ‐polyoxyethylene 400 (PMABD‐ co ‐POE) was prepared; the average chain lengths n , of the PMABD studied are 8.1 to 20.6. The thermotropic properties and the mesophase texture of the segmented copolymers were elucid…
Abstract The effects of various catalysts on the reactive blending of poly(ethylene terephthalate) (PET) and bisphenol A polycarbonate (PC) was investigated. The various catalysts employed for PET syntheses, Ti(OBu)4, SmL 3 , EuL 3 , Ca + Sb, CeAc 3 , Er(NO 3 ) 3 ·B 12 C 4 and Tb (acac) 3 ·diPy (where L is o ‐formylph…
Theoretical vibrational spectra of polypyrrole are presented, based on a single-periodic-chain model and harmonic potential in-plane and out-of-plane parameters transferred from the pyrrole molecule. The infrared-absorption intensities were included in the calculations for the first time in polypyrrole. Experimental s…
Recent experiments in metallic solid solutions have revealed interesting correlations between static pair-displacements and the ordering behavior of these alloys. This paper discusses a simple theoretical model which successfully explains these observations and which provides a natural framework for analyzing experime…
A very short GaGa bond, stabilized by carborane moieties, is present in the digallane 1, which is air- and moisture-sensitive, and soluble in both polar and nonpolar organic solvents. The coordination of each Ga atom to the respective C2B3 carborane face is “slip distorted”. • = H, □ = SiMe3.
The MnIVO unit in the five-coordinate oxo(porphyrinato)manganese(IV) complex 2, which is formed by oxidation of the bromo(porphyrinato)manganese(III) complex 1 with potassium peroxycarbonate, was characterized by X-ray absorption spectroscopy. The relatively long MnO bond (1.69±0.03 Å) is probably attributable to th…
The reversible photoisomerization of the helical thioxanthenes 1 and 2 leads to photostationary states with large diastereomeric excesses. These compounds are promising starting materials for optical data storage devices.
The laminated ferroelectric 180 degrees domain structure optically observed in uniaxial ferroelectric KDP is periodic along the normal to the domain walls. Each half-period of the domain structure is characterized by the first four pre-fractals of the pentad Cantor sets. In order to investigate the thermodynamic stabi…
Capacitively coupled radio frequency (cc-rf) plasmas offer advantages over microwave (MW) induced plasmas for the growth of large area homogeneous thin films. However, conventionally designed cc-rf sources lead, at best, to extremely poor quality material when diamond growth is attempted. The first complete diamond ov…
Nonresonant third-order harmonic generation from CdS clusters encapsulated in zeolite A and X was observed at a fundamental wavelength of 1900 nm. To avoid scattering from the surfaces of the small zeolite crystals, the powder samples were dispersed in a liquid with nearly the same refractive index as that of the samp…