Graphene/Li-Ion battery

Density function theory calculations were carried out to clarify storage states of Lithium (Li) ions in graphene clusters. The adsorption energy, spin polarization, charge distribution, electronic gap, surface curvature and dipole momentum were calculated for each cluster. Li-ion adsorbed graphene, doped by one Li atom is spin polarized, so there would be different gaps for different spin polarization in electrons. Calculation results demonstrated that a smaller cluster between each two larger clusters is preferable, because it could improve graphene Li-ion batteries; consequently, the most proper graphene anode structure has been proposed.Comment: 19 pages, 7 figures, 1 tabl

3_D surface stereometry of Ag/DLC nanocomposite prepared by RF-PECVD

In this study, a stereometric analysis of the three-dimensional (3-D) surfaces of the Ag/diamond-like carbon (DLC) nanocomposite films was done. The nanocomposite thin films were fabricated by Radio Frequency Plasma-Enhanced Chemical Vapour Deposition (RF-PECVD). The 3-D surface microtexture was studied by high-resolution Atomic Force Microscopy (AFM) records combined with statistical analyses. More detailed information about surface statistical parameters and topographic features of analyzed samples were performed. The statistical parameters relating to the segmented motifs consistent with ISO 25178-2: 2012 have been generated using MountainsMap® Premium software. The analysis was performed by modeling Ag/DLC nanocomposite surface microtexture based on motif analysis (detection of essential characteristics in terms of surface dimensions, volume, curvature, shape) to be included in computer interactive simulation algorithms

Review on graphene spintronic, new land for discovery

The science for processing and control of electron spins is referred to as “Spintronics”. Metals, semiconductors, and in particular carbon-based materials are especially interesting in this respect due to their spin arrangements. Graphene, a hexagonal two-dimensional structure of carbon has attracted much attention due to its spin relaxation mechanism and many other advantages. We discuss the origin of graphene’s spin in nano-scale devices. A key concept for understanding spin polarized state properties of graphene is Lieb’s theorem, according to which one can predict whether a graphene structure is spin-polarized. However, this theorem cannot predict anything about magnetic properties of graphene. Lieb’s theorem has many important consequences including spin polarization of a supercell, and that quasi-localized states populating complementary sublattices interact with each other. There exists a large number of theoretical works, which study graphene spin polarization using theoretical methods to investigate the magnetic properties of graphene. We will discuss these theoretical works and their important consequences. In addition, several key experimental results for graphene’s spin Engineering are produced

Iron nanoparticles embedded in carbon films: structural and optical properties

In the present work amorphous hydrogenated carbon films with sputtered iron nanoparticles (Fe NPs @ a-C:H) were deposited by co-deposition of RF-sputtering and RF-plasma enhanced chemical vapor deposition methods using acetylene gas and iron target on quartz and silicon substrates. Samples were prepared in different initial pressures and during constant deposition time. The crystalline structure of Fe NPs @ a-C:H was studied using X-ray diffraction and selected area electron diffraction patterns. The X-ray photoelectron spectroscopy analysis presents that increasing the initial pressure decreases the atomic ratio of Fe/C and the sp3-hybridized carbon content in prepared samples. The transmission electron microscope image shows the encapsulated Fe NPs in carbon films. The optical properties and localized surface plasmon resonance (LSPR) of samples were studied using UV-visible spectrophotometry, which is shown that increasing of Fe content decreases the intensity of LSPR peak and increases the optical band gap

Logarithmic Operators in Conformal Field Theory and The

It is shown explicitly that the correlation functions of Conformal Field Theories (CFT) which posses the logarithmic operators are invariant under the Borel subalgebra of W1 -algebra constructed by tensor-operator algebra of sl(2; IR). The general expression for three and four-point correlation functions which posses logarithmic operators is calculated. The operator product expansion (OPE) coefficients of general logarithmic CFT are given up to third level. 1 e-mail address: [email protected] 1 Introduction It has been shown by Gurarie [1], that in the OPE of two given local fields which has at least two fields with the same conformal dimension, one can find some operators with a special property, known as logarithmic operators. As discussed in [1], these operators with the ordinary operators form the basis of the Jordan cell for the operator L 0 . The logarithmic operators [1] are of interest, because there are many physical theories which possess such operators, for exampl..

The effect of coated diamond-like carbon thin films on polymer tooth based denture: Micro-morphology and fractal feature studies

To consider improving the micromorphology study of dentures combined with biocompatibility in recent years, we study hybrid organic–inorganic materials and diamond-like carbon coated on tooth-based dentures by the sol–gel and the RF sputtering method, respectively. Afterward, the effect of such material coating on the surface roughness and surface topography of dentures was evaluated. Aimed at this, 3D atomic force microscope images were analyzed via MountainsMap® Premium software, which divided the surface into peaks and pits through the watershed segmentation algorithm. This method made motif analysis possible by detecting the surface dimensions, curvature, volume, perimeters, shape, structure, etc., and the obtained statistics indicate interesting results for the regular and irregular topography and the surface of the prepared samples. In addition, the energy-dispersive x-ray spectrum illustrates the existence of N, C, O, Na, and Si in all samples, with the maximum value of C in the diamond-like carbon coated sample, which is because of the highest value of carbon in diamond-like carbon. Scanning electron microscope images also present a series of grooves on the surface with small randomly oriented cracks. The linear interpolation type shows that the surface of diamond-like carbon coated on the hybrid-control sample has the most irregular topography while the most regular topography was found in the hybrid coated control sample