Materials Literature
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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…
Complete absorption spectra of three liquid crystals with different conjugation length were measured in the 0.185–20 μm spectral range. In the ultraviolet region, the absorption is dependent on whether σ or π electrons are involved. In the mid and long infrared regions, several localized molecular vibration bands exis…
The supramolecular organization of Congo Red molecules was studied to approach an understanding of the unusual complexation characteristics associated with the liquid crystalline nature of this dye. Differential scanning calorimetry (DSC) and nmr data indicate that Congo Red assembly arrangements differ in water and s…
We present ultrafast optical studies on nanoshells, which consist of a nanoscale ${\mathrm{Au}}_{2}\mathrm{S}$ dielectric core surrounded by an ultrathin Au shell. The plasmon frequency of these nanoparticles can be controlled by varying the ratio of the core diameter to shell thickness. By tuning this plasmon peak, w…
Ti-containing and W-containing diamond-like hydrocarbon coatings have been synthesized by glow discharge reactive magnetron sputter deposition in an Ar/CH4 mixture. it is shown that these metal-containing hydrocarbon coatings consist of nanocrystalline TiC and WC embedded in an amorphous hydrocarbon matrix and are thi…
SiO 2 films containing Si nanocrystals (nc-Si) and Er were prepared and their photoluminescence (PL) properties were studied. The samples exhibited PL peaks at 0.8 and 1.54 μm, which could be assigned to the electron-hole recombination in nc-Si and the intra-4f transition in Er3+, respectively. Correlation between the…
Ab initio calculations of the electronic energy loss of ions moving in aluminum crystal are presented, within linear-response theory, from a realistic description of the one-electron band structure and a full treatment of the dynamical electronic response of valence electrons. For the evaluation of the density-respons…
We study electronic properties of solids with correlated d electrons which could be described by a multiband Hubbard Hamiltonian in the weak-interaction case, $U/w<1$. The one-electron part of the many-body Hamiltonian is described by a tight-binding LMTO method. The many-body part is treated by non-selfconsistent FLE…
We propose a consistent treatment of the applied external stress on a two-dimensional dislocation systems by using the analogy between our model and the layered superconductors. Using the results of a mathematically rigorous, real-space renormalization-group (RG) calculations in the latter model we extend the original…
The momentum and energy dependence of the matrix elements for direct and indirect transitions across the band gap is studied both theoretically and experimentally. The accepted theory for the inelastic scattering cross section of fast electrons by condensed matter is extended to show how the nature of a transition can…
Nanostructured CoFe 2 O 4 particles were prepared by a sonochemical approach, first by preparation of the amorphous precursor powders, followed by heat treatment at relatively very low temperatures. The precursor was prepared by sonochemical decomposition of solutions of volatile organic precursors, Fe(CO) 5 and Co(NO…
The proper development of the musculoskeletal system in the tetrapod limb requires the coordinated development of muscle, tendon and cartilage. This paper examines the morphogenesis of muscle and tendon in the developing avian hind limb. Based on a developmental series of embryos labeled with myosin and tenascin antib…
The optimized geometries of carbon allotropes related to graphite, called graphyne, graphdiyne, graphyne-3, and graphyne-4, as well as their electronic band structures were calculated using a full-potential linear combination of atomic orbitals method in the local-density approximation. These carbon allotropes consist…