Materials Literature
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This chapter deals with electron diffraction and imaging in the transmission geometry at kilovolt and higher beam energies for the purposes of crystal structure determination. Techniques such as low-energy electron diffraction, gas electron diffraction and reflection electron diffraction are not considered. Following…
The Patterson function is a phaseless Fourier synthesis of diffraction intensities that corresponds to an autocorrelation of electron densities in a crystal cell. Prominent non-origin peaks in a Patterson function represent interatomic vectors; deconvolution of this information can be used to locate heavy atoms, known…
The ubiquitous static friction (stiction) and adhesion forces comprise a major obstacle in the manipulation of matter at the nanoscale (Falvo et al 1999 Nature 397 236; Urbakh M et al 2004 Nature 430 525). In this work it is shown that a surface coated with vertically aligned carbon nanotubes—a nanotube forest—acts as…
The compatibility of low-dimensional thermoelectric materials in forms such as thin films and nanowires for use in thermoelectric coolers is examined. First-order thermoelectric theory predicts that the cold and hot junction temperatures of a thermoelectric circuit are governed solely by the nondimensional figure of m…
Zinc-blende-structured MnAs epitaxial films were grown on GaAs (100) substrates with InAs buffer layer. The resistivity and the Hall resistance behavior at various temperatures indicate that the MnAs thin film is half-metallic in nature. A MnAs∕GaAs∕MnAs spin-valve structure, fabricated utilizing half-metallic MnAs th…
Abstract Stannous oxide (SnO 2 ) thin film is one of the most widely used n‐type transparent semi‐conductor films in electronics, electro‐optics and solar energy conversion. By achieving controlled non‐stoichiometry, we can get good transparency and high electrical conductivity simultaneously in SnO 2 thin films. Dy a…
Oxygen atom adsorption onγ-TiAl(111) surface is studied using first-principles approach.The adsorption site with more Ti atoms as its nearest neighbors on the surface layer is found to be preferred.Adsorption energy differences between different adsorption sites become smaller with increasing of oxygen coverage.Electr…
Of the processes that reduce the intensity of X-rays passing through matter, photoelectric absorption, scattering and extinction are important for the X-ray wavelengths used in crystallography. This chapter discusses each in turn. Different kinds of absorption corrections are described and parameters for use in calcul…
Abstract The molecular symmetry of all the existing organic ferroelectrics was analyzed with an intention to develop a criterion to search for new low molecular weight organic ferroelectric. We present here a summery of the analysis; it is conclude that in order to exhibit ferroelectricity in crystalline state the mol…
Solid state reaction silicon nanocrystals (Si nc’s) of an average size of 10nm have been synthesized. Charge transport characteristics have been investigated as a function of temperature and voltage. From 305to400K, it is found that space-charge-limited current (SCLC), with an exponential distribution of trapping stat…
This is version 2.0.11 of the macromolecular CIF dictionary (mmCIF), dated 300 May 2007. The philosophy behind this dictionary and the history of its development are described in Chapter 8.1. A detailed commentary on the use of the dictionary is given in Chapter 3.11.
It is shown that reduction of the symmetry of the shape of almost spherical nanocrystals to that of a three axial ellipsoid or lower leads to a splitting of the exciton radiative doublets into linearly polarized components. The splitting is a result of a combined action of the distortion of the boundary conditions and…
We introduce a mesoscale technique for simulating the structure and rheology of block-copolymer melts and blends in hydrodynamic flows. The technique couples dynamic self-consistent field theory with continuum hydrodynamics and flow penalization to simulate polymeric fluid flows in channels of arbitrary geometry. We d…
Molecular dynamic simulations are performed to investigate the melting process of two-dimensional clusters of classical charged particles trapped in an anisotropic parabolic potential. The confined particles interact through a repulsive potential. We find that the eccentricity of the confinement potential strongly aff…
Magnetic domain formation in thin films of La1−xSrxMnO3 (LSMO) with x=0.2 and 0.4 epitaxially grown on stepped SrTiO3 (001) substrates has been investigated by photoelectron emission microscopy. The magnetic domains show a stripe structure elongated along the step directions, indicating uniaxial magnetic anisotropy in…
The filling fraction limit (FFL) for potassium in skutterudite CoSb3 has been investigated by first-principles methods. The FFL is derived by minimizing the formation energy of a reaction that includes the formation of both the filled skutterudite KyCo4Sb12 and the potential secondary phases KSb and CoSb2 when doping…
The g(44) grating is an electroholographic transmission grating in which the applied field is perpendicular to both the grating vector and the wave vector of the incident beam. It is argued that in this configuration the incident beam traverses through a periodically rotating index ellipsoid. It is shown that in the g…
The n-ZnO single nanowire/p+-Si heterojunctions are fabricated using two types (A and B) of ZnO nanowires. Both types of nanowires are synthesized using the vapour phase transport method. Nanowires A, with growth direction along the high index, are grown on Si substrates. Nanowires B, with growth direction along [0001…
Based on the integral theorems for mean curvature and Gauss curvature, geometric conservation laws for perfect Y-branched carbon nanotubes are presented. From the conservation laws, simple geometric regulations observed by spontaneous Y-branched carbon nanotubes are revealed, i.e. the angle between two neighbouring br…
This paper reports on an attempt to use CD and CD/PHB ICs as nucleation agents for PHB in a high-speed melt spinning process. At first rheological and thermal properties of the nucleated melts are determined in order to assess the influence of the nucleating agents. Then spinning tests are carried out. Thermal and tex…