Lattice Constant

We discuss about the antibacterial activities of Silver nanoparticles and compare them on both Gram negative and Gram positive bacteria in this investigation. The activities of Silver nanoparticles synthesized by electrolysis method are more in Gram (-) than Gram (+) bacteria. First time, we increase its antibacterial activities by using electrical power while on electrolysis synthesis and it is confirmed from its more antibacterial activities (For Escherichia coli bacteria). We investigate the changes of inner unit cell Lattice constant of Silver nanoparticles prepared in two different methods and its effects on antibacterial activities. We note that slight change of the lattice constant results in the enhancement of its antibacterial activities.

A density functional theory codes FHI-aims is used to investigate the material properties of AlAs bulk crystalline structures. The code has several input parameters or variables some of which should be optimized. In the FHI-aims code we study different phases of AlAs crystalline structure and the ground state cohesive properties of the most stable structure of AlAs was computed within GGA and LDA of the density-functional theory. The results of computations shows that the ground state equilibrium properties of and AlAs such as Lattice constants, cohesive energies and Bulk modulus are in agreement with experimentally found values within reasonable percentage errors.

A near infrared waveguide photodetector in Si-based ternary Si₁−x−yGexCy alloy was demonstrated for 0.85~1.06 µm wavelength fiber-optic interconnection system applications. Two sets of detectors with active absorption layer compositions of Si₀.₇₉Ge₀.₂C₀.₀₁ and Si₀.₇₀Ge₀.₂₈C₀.₀₂ were designed. The active absorption layer has a thickness of 120~450 nm. The external quantum efficiency can reach ~3% with a cut-off wavelength of around 1.2 µm. Singapore-MIT Alliance (SMA)

In this work, a semi-empirical relation is elaborated in terms of lattice constant (a˳) and product of ionic charges (Z a Z b Z c) for the calculation of bulk moduli (in GPa) of A 2 BX 6 (A: large cation, B: transition metal and X: halide anions) structured materials. Z a Z b Z c and a˳ were related through bulk modulus through linear regression. These two parameters yield a straight regression line, when plotted but fall on different positions due the variation in bulk modulus values. The calculated values of bulk moduli reflecting elastic characteristics are in close agreement with other available values. As, these values are only differ by average of 3% from values of literature. Moreover, the regression resulted in a good values of correlation coefficient (R=0.77) and Probability (P=0.001). These all show the accuracy and 2 | P a g e reliability of the current work. The technique adopted in this work will be helpful to material scientists for finding new materials with preferred elastic characteristics among structurally similar materials, also the calculated data will act as reference for upcoming investigation of the studied compounds.

Dielectric ceramics in the BaO–Sm2O3–TiO2 ternary system have been synthesized and characterized. Solid solutions with the formula Ba6−3xSm8+2xTi18O54 with x=0.0, 0.2–0.7 have been synthesized, which are in the vicinity of BaO·Sm2O3·4TiO2 (consistent with x=0.5) ternary system. X-ray powder diffraction (XRD) analysis of synthesized specimens has been done from which lattice parameters as a function of composition (x) were determined. Crystal

The microstructures and magnetic properties of FePt(-SiO x-C) thin films grown on TiON and TiON/TiN intermediate layers were studied. TiON possessed smaller surface energy and smaller lattice constant than TiN. With increasing TiO x doping concentration, FePt grain shape changed from semi-spherical to square and grain size was significantly reduced. Meanwhile, good perpendicular magnetic anisotropy was retained, indicating that TiON intermediate layer could achieve a good balance between island growth and epitaxial growth. Furthermore, using TiON/TiN combined intermediate layer, FePt grain size was further reduced and the opening-up of in-plane M-H loop diminished. With 45 vol.% SiO x-25 vol.% C doping, well-isolated FePt grains with an average size as small as 5.7 nm and the grain size distribution of 0.9 nm were achieved. It also exhibited good perpendicular magnetic anisotropy with an out-of-plane coercivity of 18 kOe.

Cd1-xMgxTe is a potential candidate for the top cell in two-terminal tandem solar cells. The close match of the lattice constant of MgTe with CdTe and the apparent complete miscibility of MgTe in CdTe and the rapid increase in band gap with Mg content gives flexibility to prepare material with the appropriate band gap for current-matching in a tandem solar

Recently in the field of materials science, advanced computational intelligence (CI) based approaches are gaining substantial importance for modeling the quantitative structure to properties relationship. In this study, we have used support vector regression, random forest, generalized regression neural network, and multiple linear regression based CI approaches to predict lattice constants (LCs) of complex cubic perovskites. We have collected reasonable number of perovskites compounds from the recent literature of materials science. The CI models are developed using 100 training compounds and the generalized performance is estimated for the novel 97 compounds. Our analysis highlights the improved prediction performance of CI approaches than the well-known SPuDS software, which is extensively used in crytsallography. We further observed that, for some of the compounds, the larger prediction error provided by the CI models is correlated with the structure deviation of the compounds from its ideal cubic symmetry.

The effect of ternary addition of the 3d elements Ti, V, Cr, Mn, Fe, Co and Ni to CuPt 3 to form ternary CuMPt 6 alloys on the thermal properties was investigated using high temperature X-ray diffraction method. Data obtained were utilized to determine the lattice parameters, coefficients of thermal expansion, Debye temperature and mean square displacements of an atom. It was found that the addition increases the lattice spacing, increases the degree of thermal expansion and lowers the Debye temperature.

A substrate for future atomic chain electronics, where adatoms are placed at designated positions and form atomically precise device components, is studies theoretically. Since the van der Waals force turns out inappropriately weak, adatoms have to be secured with chemical bonding to the substrate atoms, but then electronic isolation between the adatom and substrate systems is not always guaranteed. A chain model shows that good isolation is expected on an s-p crossing substrate such as Si, Ge, or GaAs through surface localization, reflecting the bulk nature of the substrate. Isolation is better if adatoms are electronically similar to the substrate atoms, and can be manipulated by hydrogenation. Chain structures with group IV adatoms with two chemical bonds, or group III adatoms with one chemical bond, are semiconducting, reflecting the surface nature of the substrate. These structures are unintentionally doped due to the charge transfer across the chemical bonds. Physical properties of adatom chains have to be considered for the unified adatom and substrate systems.

Stimulated by recent progress in atom manipulation technology, the electronic properties of periodic structures artificially created with atoms on a substrate surface are studied, where constituent atoms are isolated from substrate atoms and interact with one another through neighboring‐atom interactions. By reducing the lattice constant from infinity, the neighboring‐atom interaction is gradually turned on, and discrete atomic states broaden to form energy bands. Band structures of a simple one‐dimensional atomic chain, a two‐dimensional square array, and two parallel atomic chains formed by Si are calculated as a function of lattice constant using the tight‐binding theory with universal parameters. For practical lattice constants, these Si structures are all metallic due to the existence of the π band, within which the Fermi energy lies; however, at very low spacings, possible for carbon, the double chain can become insulating. For group‐II elements such as Mg, the π band and the conduction band are empty while the valence band is fully occupied. The band‐gap variation with lattice constant is reflected in the electronic properties directly: e.g., a Mg atomic chain is insulating for lattice constants greater than or less than 4.2 Å, at which the band gap disappears and the chain becomes metallic.