scholarly journals Spin Polarized Photoemission Studies of Surfaces and Thin Films

1991 ◽  
Vol 231 ◽  
Author(s):  
Peter D. Johnson ◽  
N.B. Brookes ◽  
Y. Chang
Keyword(s):  
Binding Energy ◽  
First Principles ◽  
Magnetic Coupling ◽  
Interface State ◽  
First Principles Calculation ◽  
Layer By Layer ◽  
Minority Spin ◽  
Interfacial Electronic Structure ◽  
Spin Polarized ◽  
Magnetic States

AbstractSpin polarized photoemission is used to study the magnetic states associated with the clean iron (001) surface. These studies reveal evidence for a minority spin surface state in agreement with a first principles calculation. Studies of the same surface with silver and chromium epitaxial overlayers reveal evidence for interface states derived from this state found on the clean surface. In the case of the silver overlayer the binding energy of the new state is found to be dependent on the layer by layer thickness of the overlayer. With chromium overlayers the binding energy for the same interface state does not show the same thickness dependence. However a second interface state is observed immediately below the Fermi level. These changes in the interfacial electronic structure have implications for any modelling of magnetic coupling in multilayers dependent on the magnetic properties of the interface.

scholarly journals Oxidation and Magnetic States of Chalcоpyrite CuFeS2: A First Principles Calculation

2014 ◽  
Vol 116 (6) ◽  
pp. 961-964
Author(s):  
V. V. Klekovkina ◽  
R. R. Gainov ◽  
F. G. Vagizov ◽  
A. V. Dooglav ◽  
V. A. Golovanevskiy ◽  
...  
Keyword(s):  
First Principles ◽  
First Principles Calculation ◽  
Magnetic States

Search for Effective Sites of Proximity Gettering Induced by Ion Implantation in Si Wafers with First Principles Calculation

2015 ◽  
Vol 242 ◽  
pp. 271-276
Author(s):  
Sho Shirasawa ◽  
Koji Sueoka
Keyword(s):  
Heat Treatment ◽  
Binding Energy ◽  
Ion Implantation ◽  
Point Defects ◽  
First Principles ◽  
First Principles Calculation ◽  
Manufacturing Processes ◽  
Intrinsic Point Defects

Fe, Ni and Cu atoms diffuse very quickly in Si and are the main targets for metal gettering. W, Hf, and Mo atoms, for example, which diffuse very slowly in Si have also recently become gettering targets in addition to these metals. Therefore, proximity gettering techniques by using ion implantation are being considered. Not only implanted elements but intrinsic point defects exist and form several complexes after the heat treatment for Si crystal recovery. This research systematically investigated the binding energy of twelve important metals (Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Hf, Ta, and W) with implanted dopants (B, C, P, and As) and their complexes with intrinsic point defects (vacancies (Vs) and self-interstitials (Is)) by using first principles calculation. These data should be useful in the design of proximity gettering in LSI manufacturing processes.

Site Preference of Refractory Elements in Ni-Based Single-Crystal Superalloys Alloying with Ru: From First Principles

2012 ◽  
Vol 554-556 ◽  
pp. 3-12
Author(s):  
Jian Jun Cui ◽  
Fei Sun ◽  
Jian Xin Zhang
Keyword(s):  
Binding Energy ◽  
Single Crystal ◽  
First Principles ◽  
First Principles Calculation ◽  
Partial Density ◽  
Site Preference ◽  
Strengthening Effect ◽  
Mulliken Population ◽  
Calculation Results ◽  
Partitioning Behavior

A first principles calculation method was used to investigate the site preference of Ruthenium (Ru) at the γ/γ′ interface in Ni-based single-crystal superalloys. The calculation results show that the addition of Ru can decrease the total energy and the binding energy of γ/γ′ interface, which may result in an improved microstructure stability of Ni-based single-crystal superalloys. Moreover, by calculation, it is also found that Ru can stabilize both γ and γ′ phases and have a preference for Ni site at the coherent γ/γ′ interface. When Ru substitutes the central Ni at the γ/γ′ interface, a reverse partitioning of W, Re and Cr occurs; while the partitioning behavior of Mo is not affected. The influence of Ru on the partitioning behavior of W, Re and Cr in γ′-Ni3Al was studied by Dmol3 calculation as well. The calculation results show that W, Re and Cr have a preference for Ni site in γ′- Ni3Al with Ru alloying. When Ru substitutes the central Ni atom, the site preference of W, Re and Cr varies accordingly. Furthermore, electronic structure analysis of γ/γ′ interface and γ′-Ni3Al in terms of Mulliken population and partial density of states (PDOS) was performed to understand the alloying mechanism of Ru in Ni-based single-crystal superalloys. The results show that the strengthening effect of Ru alloying is mainly due to the reduction in binding energy of Ru as well as a p-orbital hybridization between Ru and the host atoms.

Adsorption of Methane on Pristine and Al-Doped Graphene: A Comparative Study via First-Principles Calculation

2012 ◽  
Vol 602-604 ◽  
pp. 870-873 ◽  
Author(s):  
Wei Zhao ◽  
Qing Yuan Meng
Keyword(s):  
Charge Transfer ◽  
Binding Energy ◽  
Comparative Study ◽  
First Principles ◽  
First Principles Calculation ◽  
Pristine Graphene ◽  
First Principles Calculations ◽  
Graphene Surface ◽  
Doped Graphene ◽  
Adsorption Of Methane

The adsorption of methane (CH4) molecule on the pristine and Al-doped (4, 8) graphene was investigated via the first-principles calculations. The results demonstrated that, in comparison to the adsorption of a CH4molecule on the pristine graphene sheet, a relatively stronger adsorption was observed between the CH4molecule and Al-doped graphene with a shorter adsorption distance, larger binding energy and more charge-transfer from the graphene surface to the CH4molecule. Therefore, the Al-doped graphene can be expected to be a novel sensor for the detection of CH4molecules in future applications.

scholarly journals Oxidation and magnetic states of chalcopyrite CuFeS2: A first principles calculation

2014 ◽  
Vol 116 (6) ◽  
pp. 885-888 ◽  
Author(s):  
V. V. Klekovkina ◽  
R. R. Gainov ◽  
F. G. Vagizov ◽  
A. V. Dooglav ◽  
V. A. Golovanevskiy ◽  
...  
Keyword(s):  
First Principles ◽  
First Principles Calculation ◽  
Magnetic States

scholarly journals Effect of metal decoration on sulfur-based gas molecules adsorption on phosphorene

2021 ◽  
Author(s):  
Yonghu Wang ◽  
Shuangying Lei ◽  
Ran Gao ◽  
Xiaolong Sun ◽  
Jie Chen
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
First Principles ◽  
Density Functional ◽  
Metal Clusters ◽  
First Principles Calculation ◽  
Functional Theory ◽  
Gas Molecule ◽  
Metal Decoration ◽  
Gas Molecules

Abstract Using the first-principles calculation based on density functional theory (DFT), we systematically studied the adsorption of sulfur-based gas molecules (H2S, SO2, SO3) on various metal-decorated phosphorenes. To avoid the formation of metal clusters on the surface of phosphorene, eleven metals (Li, Na, K, Rb, Cs, Ca, Sr, Ba, Ni, La, Tl) with bulk cohesive energy less than the binding energy on the phosphorene are considered. Except for H2S on Tl-decorated phosphorene, all metal decorations can improve the adsorption strength of phosphorene to sulfur-based gas molecules, and Eads(H2S) < Eads(SO2) < Eads(SO3) for the same metal decoration case. In addition, some metal-decorated phosphorene systems exhibit interesting magnetic and electrical changes after sulfur-based gas molecule adsorptions, indicating that these metal-decorated phosphorene systems are promising to be used for the detection and removal of sulfur-based gas molecules.

scholarly journals Systematic Investigation of Gettering Effects on 4th Row Element Impurities in Si by Dopant Atoms

2009 ◽  
Vol 2009 ◽  
pp. 1-3 ◽  
Author(s):  
Koji Sueoka ◽  
Ken Kamimura ◽  
Seiji Shiba
Keyword(s):  
Binding Energy ◽  
Transition Metals ◽  
Diffusion Barrier ◽  
First Principles ◽  
Systematic Investigation ◽  
First Principles Calculation ◽  
Light Elements ◽  
Impurity Atoms ◽  
Dopant Atoms ◽  
P Type

The gettering of 4th row element impurities (K, Ca, 3d transition metals, and Zn) in Si crystals by dopant atoms was systematically investigated by first-principles calculation through evaluation of the diffusion barrier and the binding energy. The dopant atoms considered include p-type dopants (B), n-type dopants (P, As, Sb), or light elements (C, O). It was found that (1) the diffusion barrier of impurity atoms decreases with an increase in their atomic number up to Ni, (2) B atom becomes an efficient gettering center for metals except for Ni, (3) most of the metals except for Fe and Co cannot be gettered by n-type dopants, and (4) C and O atoms alone do not become efficient gettering centers for the metals used in actual LSI processes. The vacancy and n-type dopant complexes (P, As, Sb) can be efficient gettering centers for Cu in n/n+ epitaxial wafers.

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