Materials Literature
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Molecular-dynamics (MD) simulation of the diffusion of water in amorphous polyethylene has been performed under a constant particle number, constant pressure, and constant temperature (NPT) conditions. The three simulation systems with the different water concentration from 0.120% (g/g) to 0.324% (g/g) were tested. A…
We report an in situ grazing incidence x-ray scattering study of the Ni/MgO (001) interface during its formation at room temperature. In-plane measurements reveal that the interface is sharp and that the epitaxial relationship is complex. In the early stages of growth, up to one monolayer of “on site” Ni, in-plane str…
We report the anchoring transition in a discotic liquid crystal, hexapentyloxy triphenylene (HPT), from edge-on to side-on alignment in a discotic phase. The topology, easy direction of orientation and the coating of the substrate with a polymer are the determining factors for the alignment and the anchoring transitio…
Rietveld analyses of neutron diffraction data collected on a series of Pb(Zr 0.5 Ti 0.5 )O 3 samples, which had been prepared by sol−gel and conventional mixed oxide methods, showed that each sample contained both rhombohedral and tetragonal PZT (Pb[Zr 1 - x Ti x ]O 3 ). The zirconium-to-titanium ratio in the two phas…
The complexes trans -[PdI 2 (CNR) 2 ], 1a − 1 e, (CNR = 3-CN−C 6 H 4 −CN ( 1a ), 4-CN−3−C 2 H 5 −C 6 H 3 −CN ( 1b ), c: 4-CN−3−Cl−C 6 H 3 −CN ( 1c ), 4-CN−1,2-(NC) 2 −C 6 H 3 ( 1d ), 4-CN−C 6 H 4 −CH 2 CN ( 1e )), have been prepared. Complex 2a forms a coordination polymer, 3, with copperbis(hexafluoroacetylacetonate)…
The lateral crystal growth rate of isotactic polystyrene lamellae developing in thin films (ranging from 20 nm to 500 nm) decreases with decreasing film thickness. The decrease in growth rate is inversely proportional to the film thickness: G ( D )= G (∞)(1- d / D ), where G ( D ) is the growth rate in a film of thick…
We have studied luminescence Stokes shift and phonon-assisted luminescence in H-terminated and surface-oxidized Si nanocrystals by means of resonant excitation spectroscopy. For resonant excitation at energies within a broad luminescence band, TO- and TA-phonon related structures in luminescence spectra are observed i…
We have fabricated a novel device that acts as a quarter-wave plate at normal incidence and as a polarizing beam splitter at an angle of incidence of ~40 deg . The device is made from a multilayer (SiO(2) /Si(3)N(4)) surface-relief zeroth-order one-dimensional grating with a period of 0.3 mum . The device is designed…
Low-energy electron diffraction patterns, produced from quasicrystal surfaces by ion sputtering and annealing to temperatures below \ensuremath{\sim}700 K, can be assigned to various terminations of the cubic CsCl structure. The assignments are based upon ratios of spot spacings, estimates of surface lattice constants…
Comparison of the isotypic solid-state structures of disodium zinc diphosphate (Na2ZnP2O7) and disodium zinc diphosphate doped with europium (Na1.94Eu0.02ZnP2O7) shows the europium to share a sodium site and to exist at the intersection of two mirror planes in the layer-like structure. The emission characteristics of…
Interstitial-substitutional carbon pairs $({\mathrm{C}}_{i}{\mathrm{C}}_{s})$ in silicon display interesting metastable behavior associated with two different structural configurations. In this work, we perform extensive ab initio calculations on this system. Our results show the following. (i) The metastable configur…
The occupied and unoccupied electronic structures of disordered ${\mathrm{Au}}_{x}{\mathrm{Pd}}_{1\ensuremath{-}x}$ alloys are studied by valence-band photoemission, bremsstrahlung isochromat spectroscopy (BIS), and x-ray absorption near-edge spectroscopy (XANES). The occupied partial spectral weights (PSW's) of Au $5…
Heat capacities of Sn 2 P 2 S 6 and Sn 2 P 2 Se 6 single crystals were measured at temperatures between 10 and 380 K for the former and between 10 and 350 K for the latter using an adiabatic calorimeter. The heat capacity anomaly due to the ferroelectric-paraelectric phase transition occurred at 337.25 ±0.10 K in Sn 2…
The elementary excitations of a model Hamiltonian that captures the low-energy behavior of a simple twofold-degenerate Hubbard Hamiltonian, with Hund's rule coupling, is studied. The phase diagram in the mean-field limit and in a two-site approach reveals a rich variety of phases where both the orbital and the spin de…
Epitaxial Bi4Ti3O12 (BTO) thin films were deposited on MgO(001) substrates using Pt layers as top and bottom electrodes. In spite of the apparently symmetric capacitor structure, polarization–voltage measurements revealed strong imprint failures and current–voltage measurements showed rectifying behaviors. Imprint pul…
The second order nonlinear response from 4 nm diam gold clusters embedded in an alumina matrix deposited on a pure silica substrate has been recorded as a function of the wavelength of the fundamental incident beam. The spectrum exhibits a narrow resonance band peaked at 520 nm as a result of the coupling of the secon…
A technique for the accurate determination of secondary electron (SE) yield of insulators due to low-kV electron beam is presented. It is based on a capacitatively coupled charge measurement by subjecting the insulating film to a controlled pulsed electron beam in a scanning electron microscope. SE emissions from seve…
Polycrystalline pyridinium periodate has been studied over a wide range of temperature by differential thermal analysis, proton nuclear magnetic resonance (NMR) spectra and relaxation and complex dielectric permittivity measurements. Two solid-solid phase transitions at 210 and 323 K have been revealed and the pyridin…
The origin of the resistivity anomaly at 120 K in the layered pnictide oxide Na 2 Ti 2 Sb 2 O is discussed on the basis of tight-binding band structure calculations. The Fermi surface of this material is shown to result from the superposition of a two-dimensional and four pseudo-one-dimensional components. It is propo…
The room-temperature oxygen-induced $(2\ifmmode\times\else\texttimes\fi{}2)p4g$ clock reconstruction of Rh(001) has been investigated by low-energy alkali ion scattering, recoiling spectrometry, low-energy electron diffraction (LEED), and three-dimensional classical scattering simulations. The oxygen atoms are confirm…