Search results for "anisotropy"
showing 10 items of 912 documents
"Figure 3.0" of "Measurements of Higher-Order Flow Harmonics in Au+Au Collisions at sqrt(s_NN) = 200 GeV"
2020
Charged hadron azimuthal anisotropy $v_2$ and $v_3$ vs centrality in Au+Au collisions at 200 GeV. The corresponding Npart value to each centrality is shown in Fig.3.2.
Electronic structure and properties of MAu and MOH, where M = Tl and Nh: New data
2018
Abstract Properties of the MAu and MOH (M = Tl and element 113, Nh) molecules were calculated using the 2c-DFT method. The obtained data are needed for evaluation of reactivity of Nh studied by gas-phase chromatography experiments. Results show that Nh should be less reactive (or more volatile) than Tl, both with respect to gold and the hydroxyl group. The reason for that are strong relativistic effects on the valence 7s and 7p electron shells. In difference to the atoms, NhOH may be less volatile than TlOH due to its larger both dipole moment and anisotropic polarizability.
Problem of the magnetic anisotropy in orbitally degenerate exchange and mixed-valence clusters
2003
Abstract This contribution summarizes the results obtained in the problem of orbital degeneracy of the metal ions in exchange coupled and mixed-valence (MV) clusters. The theory of the double exchange is generalized and the orbitally degenerate systems are considered. The orbitally dependent double exchange parameter is deduced for the singlet–triplet and triplet–triplet transition metal pairs in three high-symmetric topologies. A new effective Hamiltonian of the magnetic exchange between the ions with unquenched orbital angular momenta is discussed. The technique of the irreducible tensor operators is applied to the problem of the kinetic exchange in these kind of metal clusters. Strong ma…
Mossbauer study on the distribution of iron in high coercivity chromium dioxide particles
1992
/sup 57/Fe Mossbauer spectroscopy is applied to determine the level of iron doping in high-coercivity CrO/sub 2/ particles. It is found that, compared with the conventional preparation process, the particles contain an increased amount of Fe/sup 3+/ ions in the CrO/sub 2/ crystal lattice, giving rise to higher magnetocrystalline anisotropy. This is reflected in coercivities up to over 900 Oe. All samples contain as a secondary iron-containing phase some (Cr/sub 1-x/Fe/sub x/)/sub 2/O/sub 3/. The valence of the iron doping is predominantly +3; very weak signals in the Mossbauer spectra suggest the existence of Fe/sup 4+/ in an amount 2-3% of the total number of iron atoms. >
Natural optical anisotropy of h-BN: Highest giant birefringence in a bulk crystal through the mid-infrared to ultraviolet range
2018
The giant birefringence of layered h-BN was demonstrated by analyzing the interference patterns in reflectance and transmittance measurements in the mid-infrared to the deep ultraviolet energy range. The refractive index for polarization perpendicular to the c axis is much higher than the refractive index for polarization parallel to the c axis, and it displays a strong increase in the ultraviolet range that is attributed to the huge excitonic effects arising from the unique electronic structure of h-BN. Thus, h-BN is shown to exhibit a giant negative birefringence that ranges from -0.7 in the visible to -2 in the deep ultraviolet close to the band gap. The electronic dielectric constants f…
Effects of fabrication on the mechanics, microstructure and micromechanical environment of small intestinal submucosa scaffolds for vascular tissue e…
2013
In small intestinal submucosa scaffolds for functional tissue engineering, the impact of scaffold fabrication parameters on success rate may be related to the mechanotransductory properties of the final microstructural organization of collagen fibers. We hypothesized that two fabrication parameters, 1) preservation (P) or removal (R) of a dense collagen layer present in SIS and 2) SIS in a final dehydrated (D) or hydrated (H) state, have an effect on scaffold void area, microstructural anisotropy (fiber alignment) and mechanical anisotropy (global mechanical compliance). We further integrated our experimental measurements in a constitutive model to explore final effects on the micromechanic…
Higher-order Hamilton–Jacobi perturbation theory for anisotropic heterogeneous media: dynamic ray tracing in Cartesian coordinates
2018
With a Hamilton–Jacobi equation in Cartesian coordinates as a starting point, it is common to use a system of ordinary differential equations describing the continuation of first-order derivatives of phase-space perturbations along a reference ray. Such derivatives can be exploited for calculating geometrical spreading on the reference ray and for establishing a framework for second-order extrapolation of traveltime to points outside the reference ray. The continuation of first-order derivatives of phase-space perturbations has historically been referred to as dynamic ray tracing. The reason for this is its importance in the process of calculating amplitudes along the reference ray. We exte…
Magneto-optical effects in multilayers illuminated by total internal reflection
1999
This paper describes the magneto-optical effects of metallic multilayers under the condition of total internal reflection. In the framework of Green’s dyadic technique, we detail a practical and at time-consuming scheme to compute accurately the optical properties of anisotropic multilayers deposited on a substrate. We present numerical simulations which account for the variation of the angle of incidence at a fixed wavelength and for the variation of the wavelength at fixed angle of incidence. The Kerr rotation is found to increase significantly around the critical angle for total reflection. We also discuss the importance of plasmon effects in the structure of the Kerr rotation spectra. @…
Simple model for the vibrations of embedded elastically cubic nanocrystals
2010
The purpose of this work is to calculate the vibrational modes of an elastically anisotropic sphere embedded in an isotropic matrix. This has important application to understanding the spectra of low-frequency Raman scattering from nanoparticles embedded in a glass matrix. First some low frequency vibrational modes of a free cubically elastic sphere are found to be nearly independent of one combination of elastic constants. This is then exploited to obtain an isotropic approximation for these modes which enables to take into account the surrounding isotropic matrix. This method is then used to quantatively explain recent spectra of gold and copper nanocrystals in glasses.
Spinodal decomposition of a two-dimensional model alloy with mobile vacancies
1991
Abstract Monte Carlo simulations are performed for the initial stages of phase separation in a model binary alloy (AB), where unmixing is caused by a repulsive energy between atoms of different kind ( e AA = e BB = e ), and a small fraction c v of mobile vacancies is present (typically c v = 0.04.) Unlike previous work, where interdiffusion was modelled in an unrealistic way by direct interchange of A and B atoms for c v = 0, were use the vacancy mechanism of diffusion: A-atoms may jump to vacant sites with a rate Γ A and B-atoms may jump to vacant sites with a rate Γ B , no direct A–B interchange being permitted. It is shown that the overall time-scale on which phase separation proceeds ty…