Search results for "layer"
showing 10 items of 2667 documents
Morphology and electronic structure of bcc Co(110) and fcc/hcp Co(111) on Fe(110) investigated by STM and STS
2009
Abstract We report on the growth of ultrathin epitaxial Co films on Fe(1 1 0) examined by scanning tunneling microscopy and spectroscopy (STM and STS). At room temperature Co forms pseudomorphic, ideally ordered body-centered cubic (bcc) layers for the first two monolayers as confirmed by atomically resolved STM images. This is in contrast to the related case of Co/Cr(1 1 0) where a superstructure occurs in the second layer. The third monolayer forms a close-packed structure and causes a transformation of the buried second monolayer into a close-packed structure. The Fe(1 1 0) substrate strongly influences the electronic structure of the first Co monolayer as concluded from the dI / dU spec…
Hierarchical Self-Assembly of Supramolecular Spintronic Modules into 1D- and 2D-Architectures with Emergence of Magnetic Properties
2004
Hierarchical self-assembly of complex supramolecular architectures allows for the emergence of novel properties at each level of complexity. The reaction of the ligand components A and B with Fe II cations generates the (2 K 2) grid-type functional building modules 1 and 2, presenting spin-tran- sition properties and preorganizing an array of coordination sites that sets the stage for a second assembly step. Indeed, binding of La III ions to 1 and of Ag I ions to 2 leads to a 1D columnar superstructure 3 and to a wall-like 2D layer 4, respectively, with concomitant modulation of the magnetic properties of 1 and 2. Thus, to each of the two levels of structural complexity generat- ed by the t…
An AI Walk from Pharmacokinetics to Marketing
2009
This work is intended for providing a review of reallife practical applications of Artificial Intelligence (AI) methods. We focus on the use of Machine Learning (ML) methods applied to rather real problems than synthetic problems with standard and controlled environment. In particular, we will describe the following problems in next sections: • Optimization of Erythropoietin (EPO) dosages in anaemic patients undergoing Chronic Renal Failure (CRF). • Optimization of a recommender system for citizen web portal users. • Optimization of a marketing campaign. The choice of these problems is due to their relevance and their heterogeneity. This heterogeneity shows the capabilities and versatility …
Comparative Hybrid Hartree-Fock-DFT Calculations of WO2-Terminated Cubic WO3 as Well as SrTiO3, BaTiO3, PbTiO3 and CaTiO3 (001) Surfaces
2021
We greatly acknowledge the financial support via the ERAF Project No. 1.1.1.1/18/A/073. Calculations were performed using Latvian Super Cluster (LASC), located in the Center of Excellence at Institute of Solid State Physics, the University of Latvia, which is supported by European Union Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-Teaming Phase 2 under Grant Agreement No. 739508, project CAMART.
Surface and Thin Film Analysis by Mössbauer Spectroscopy and Related Techniques
1996
The main trend in current high-tech development is miniaturization. This holds for complex electronic devices, such as microprocessors, as well as for coatings, such as Langmuir-Blodgett coatings, optical components, such as fiber couplers, chemical devices, such as microreactors, mechanical components, such as micromotors, and many others. Development and production of components with dimensions in the micron and submicron range require the availability of appropriate analytical tools for chemical, physical, and morphological analyses. In close interaction with the development of microcomponents, many, more and more efficient, analytical methods have been developed, many of which are “surf…
A numerical simulation scheme for the albedo of city street canyons
1985
A numerical scheme is described for the calculation of effective albedo values of long city street canyons. The method is based on a generalization of the radiation model for inclined surfaces recently presented by Bruhl and Zdunkowski (1983). Calculated albedo values are compared with Aida's (1982) experimentally determined results. It is found that experiment and theory are in reasonable and in some cases in excellent agreement. Additional results obtained by varying the geometry of the street canyon as well as the surface reflectivities are shown to demonstrate the versatility of the calculation scheme.
Towards a full Heusler alloy showing room temperature half-metallicity at the surface
2007
In this article we investigate the surface spin polarization in a 100 nm Co2Cr0.6Fe0.4Al (CCFA) film grown ex situ epitaxially on MgO(100) with a 10 nm Fe buffer layer by means of spin resolved photoemission. We show that a careful in situ preparation of the sample surface leads to values for the room temperature spin polarization up to 45% at the Fermi level. To our knowledge, this is the highest value measured so far at the surface region of a full Heusler alloy at room temperature.
Structure and Dynamics of the Instantaneous Water/Vapor Interface Revisited by Path-Integral and Ab Initio Molecular Dynamics Simulations
2015
The structure and dynamics of the water/vapor interface is revisited by means of path-integral and second-generation Car-Parrinello ab-initio molecular dynamics simulations in conjunction with an instantaneous surface definition [A. P. Willard and D. Chandler, J. Phys. Chem. B 114, 1954 (2010)]. In agreement with previous studies, we find that one of the OH bonds of the water molecules in the topmost layer is pointing out of the water into the vapor phase, while the orientation of the underlying layer is reversed. Therebetween, an additional water layer is detected, where the molecules are aligned parallel to the instantaneous water surface.
Atomistic Calculations of Positron Surface States
1983
We report on the results of an atomistic, discrete-lattice calculation of positron surface states on the three principal surfaces of Al and Cu. We are able to (i) accurately reproduce the observed values and anisotropy of the binding energies, and (ii) predict the surface state life times. Furthermore, we calculate (iii) the positron lateral diffusion constant, and find it considerably enhanced over the bulk value. We also investigate (iv) the positron trapping at surface vacancies, and (v) the effect of ordered chemisorbed monolayers of oxygen. We find that the oxidation lowers the binding energy and makes the surface state unstable with respect to positronium emission on Al (100) and Al (…
Adsorption and diffusion of a molybdenum atom on theTiO2(110)surface: A first-principles study
2007
A study on the structure and energetics of a single molybdenum atom adsorbed on the $\mathrm{Ti}{\mathrm{O}}_{2}(110)$ surface is reported. All possible adsorption sites have been determined. Moreover, it is found that incorporation of the Mo atom into the first surface layer leads to considerably more stable structures than on any adsorption site. Different channels for migration of the molybdenum atom have been identified. The diffusion barriers of these channels have been determined. The results on structure and energetics are discussed by analyzing the electronic properties of the $\mathrm{Mo}∕\mathrm{Ti}{\mathrm{O}}_{2}(110)$ systems.