Measured and Calculated Electronic Structure of Ni0.40Pd0.400P0.20 and Cu0.400Pd0.400P0.20

2002 ◽  
Vol 754 ◽  
Author(s):  
D. M. C. Nicholson ◽  
Faisal M. Alamgir ◽  
Himanshu Jain ◽  
David B. Williams ◽  
Ricardo B. Schwarz
Keyword(s):  
Electronic Structure ◽  
Electronic Structures ◽  
Amorphous Structure ◽  
First Principles Calculations ◽  
Electronic Density ◽  
Local Environments ◽  
Densities Of States ◽  
Local Densities ◽  
Amorphous States ◽  
Shed Light

ABSTRACTX-ray Photoemission spectra of Ni0.40Pd0.40P0.20 and Cu0.40Pd0.40P0.20 in the amorphous states are compared to each other and to first principles calculations of the electronic density of states. The electronic structure is calculated for a previously validated amorphous model of Ni0.40Pd0.40P0.20 and for the same amorphous structure but with Cu replacing Ni. The measured and calculated electronic structures of Ni0.40Pd0.40P0.20 agree and exhibit very little charge transfer to Pd. However, the measured and calculated electronic structures of Cu0.40Pd0.40P0.20 differ considerably. In Cu0.40Pd0.40P0.20 there is a large electron transfer to Pd. The local densities of states on Pd atoms in different CuPdP local environments that arise in the amorphous model shed light on this dramatic charge redistribution.

scholarly journals The Electronic Structure of Grain Boundaries in NB

1990 ◽  
Vol 209 ◽  
Author(s):  
Erik C. Sowa ◽  
A. Gonis ◽  
X. -G. Zhang
Keyword(s):  
Electronic Structure ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Multiple Scattering ◽  
First Principles ◽  
Scattering Theory ◽  
Real Space ◽  
First Principles Calculations ◽  
Densities Of States ◽  
Local Densities

ABSTRACTWe present first-principles calculations of the electronic structure of Nb grain boundaries. These are the first such calculations for a bcc metal using the real-space multiple-scattering theory (RSMST). Local densities of states near a Σ5 twist grain boundary are compared to those for bulk Nb.

scholarly journals Effect of Zn doping on phase transition and electronic structures of Heusler-type Pd2Cr-based alloys: from normal to all-d-metal Heusler

RSC Advances ◽  
2020 ◽  
Vol 10 (30) ◽  
pp. 17829-17835
Author(s):  
Xiaotian Wang ◽  
Mengxin Wu ◽  
Tie Yang ◽  
Rabah Khenata
Keyword(s):  
Phase Transition ◽  
Electronic Structure ◽  
First Principles ◽  
Electronic Structures ◽  
Heusler Alloys ◽  
First Principles Calculations ◽  
Zn Doping

By first-principles calculations, for Heusler alloys Pd2CrZ (Z = Al, Ga, In, Tl, Si, Sn, P, As, Sb, Bi, Se, Te, Zn), the effect of Zn doping on their phase transition and electronic structure has been studied in this work.

scholarly journals First-principles study on the effects of N and Al doping on the mechanical properties and electronic structures of TiC

RSC Advances ◽  
2020 ◽  
Vol 10 (60) ◽  
pp. 36295-36302
Author(s):  
Zhinan Cao ◽  
Na Jin ◽  
Jinwen Ye ◽  
Xu Du ◽  
Ying Liu
Keyword(s):  
Mechanical Properties ◽  
Electronic Structure ◽  
Plane Wave ◽  
First Principles ◽  
Electronic Structures ◽  
First Principles Calculations ◽  
Al Doping ◽  
First Principles Study

First-principles calculations are carried out by DFT within the CASTEP plane wave code to investigate the mechanical properties and electronic structure of N and Al doped TiC.

Electronic Structure of Fluorine-Substituted YBa2Cu3O7 Superconductor

1987 ◽  
Vol 99 ◽  
Author(s):  
W. Y. Ching ◽  
Yongnian Xu ◽  
K. W. Wong
Keyword(s):  
Electronic Structure ◽  
First Principles ◽  
Electronic Structures ◽  
First Principles Calculations ◽  
Yba2cu3o7 Superconductor

ABSTRACTThe electronic structures of fluorine-substituted YBa2Cu3O7. crystals are studied by means of first-principles calculations. The most likely site of substitution is 0(1) and the most unlikely site is 0(4).

First-principles study of the electronic structure and thermoelectric properties of LaOBiCh2 (Ch=S, Se)

2017 ◽  
Vol 31 (29) ◽  
pp. 1750265 ◽  
Author(s):  
Guangtao Wang ◽  
Dongyang Wang ◽  
Xianbiao Shi ◽  
Yufeng Peng
Keyword(s):  
Electronic Structure ◽  
Thermoelectric Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Figure Of Merit ◽  
Transport Theory ◽  
First Principles Calculations ◽  
Boltzmann Transport ◽  
Boltzmann Transport Theory ◽  
Better Than

We studied the crystal and electronic structures of LaOBiSSe and LaOBiSeS using first-principles calculations and confirmed that the LaOBiSSe (S atoms on the top of BiCh2 layer and Se atoms in the inner of it) is the stable structure. Then we calculate the thermoelectric properties of LaOBiSSe using the standard Boltzmann transport theory. The in-plane thermoelectric performance are better than that along the c-axis in this n-type material. The in-plane power factor [Formula: see text] of n-type LaOBiSSe is as high as 12 [Formula: see text]W/cmK2 at 900 K with figure of merit ZT = 0.53 and [Formula: see text]. The ZT maximum appears around [Formula: see text] in a wide temperature region. The results indicate that LaOBiSSe is a 2D material with good thermal performance in n-type doping.

Vacancy induced Jahn–Teller distortion in silicon and its influence to the electronic structure

2015 ◽  
Vol 29 (24) ◽  
pp. 1550136
Author(s):  
Shuying Zhong ◽  
Xueling Lei ◽  
Lang Zhou
Keyword(s):  
Electronic Structure ◽  
Charge Density ◽  
First Principles ◽  
Electronic Structures ◽  
Crystalline Silicon ◽  
First Principles Calculations ◽  
Teller Distortion ◽  
Jahn Teller ◽  
The Difference ◽  
Jahn Teller Distortion

Atomic and electronic structures of monovacancy (V1), divacancy (V2) and ring hexavacancy (V6) in crystalline silicon are studied using first-principles calculations in periodic supercells. Our results show that the V6 defect is the most stable among V1, V2 and V6 defects, and the V2-RB structure is a little more stable than the V2-LP structure due to lower vacancy formation energy. Furthermore, it is found that both V1 and V2 undergo the Jahn–Teller (JT) distortion while V6 does not. As a result, V1 and V2 have deep levels in the gap which mainly come from the neighboring atoms to vacancy. V6 has tailing bands in the gap, and so has a more stable electronic structure than V1 and V2. In addition, the JT distortion also reflects in the band decomposed charge density and the difference charge density.

Chemical Bonding and Pseudogap in Zn- and Cd-based Compounds with Complex Hexagonal Structures

2003 ◽  
Vol 805 ◽  
Author(s):  
Y. Ishii ◽  
K. Nozawa ◽  
T. Fujiwara
Keyword(s):  
Fermi Level ◽  
Density Of States ◽  
Chemical Bonding ◽  
First Principles ◽  
Electronic Structures ◽  
Unit Cell ◽  
First Principles Calculations ◽  
Electronic Density ◽  
Electronic Density Of States ◽  
Crystal Orbital

ABSTRACTElectronic structures of hexagonal Zn-Mg-Y and Cd58Y13 compounds are studied by first-principles calculations. Both of the systems show deep pseudogap in the electronic density of states near the Fermi level and considered to be stabilized electronically. To illustrate bonding nature of electronic wavefunctions, the crystal orbital Hamilton population (COHP) is calculated for neighboring pairs of atoms in the unit cell. It is found that the bonding nature is changed from bonding to anti-bonding almost exactly at the Fermi level for Zn-Zn and Cd-Cd bonds. On the contrary, for Zn/Cd-Y bonds, both of the states below and above the pseudogap behave as bonding ones. Possible effects of the p-d hybridization are discussed.

First-principles investigation of possible martensitic transformation and magnetic properties of Heusler-type Pt2-xMn1+xIn alloys

2015 ◽  
Vol 08 (06) ◽  
pp. 1550064 ◽  
Author(s):  
Lin Feng ◽  
Wenxing Zhang ◽  
Enke Liu ◽  
Wenhong Wang ◽  
Guangheng Wu
Keyword(s):  
Magnetic Properties ◽  
Phase Transformation ◽  
Electronic Structure ◽  
Martensitic Transformation ◽  
Phase Stability ◽  
First Principles ◽  
Electronic Structures ◽  
First Principles Calculations ◽  
Magnetic Structures

The phase stability, electronic structure and magnetism of Pt 2-x Mn 1+x In (x = 0, 0.25, 0.5, 0.75, 1) alloys are studied by first-principles calculations. The possible magnetic martensitic transformation in this series has been investigated. For all the five compounds, the energy minimums occur around c/a = 1.30, and the energy differences between the austenitic and martensitic phases are large enough to overcome the resistance of phase transformation. By comparing the electronic structures of austenitic and martensitic phases, we can find that the phase stability is enhanced by the martensitic transformation. The magnetic structures of the austenitic and martensitic phases are also discussed.

scholarly journals Signature properties of water: Their molecular electronic origins

2015 ◽  
Vol 112 (20) ◽  
pp. 6341-6346 ◽  
Author(s):  
Vlad P. Sokhan ◽  
Andrew P. Jones ◽  
Flaviu S. Cipcigan ◽  
Jason Crain ◽  
Glenn J. Martyna
Keyword(s):  
Electronic Structure ◽  
Single Molecule ◽  
Molecular Model ◽  
A Priori ◽  
Coexistence Curve ◽  
Coarse Grained ◽  
Many Body ◽  
Interaction Terms ◽  
Local Environments ◽  
Amorphous States

Water challenges our fundamental understanding of emergent materials properties from a molecular perspective. It exhibits a uniquely rich phenomenology including dramatic variations in behavior over the wide temperature range of the liquid into water’s crystalline phases and amorphous states. We show that many-body responses arising from water’s electronic structure are essential mechanisms harnessed by the molecule to encode for the distinguishing features of its condensed states. We treat the complete set of these many-body responses nonperturbatively within a coarse-grained electronic structure derived exclusively from single-molecule properties. Such a “strong coupling” approach generates interaction terms of all symmetries to all orders, thereby enabling unique transferability to diverse local environments such as those encountered along the coexistence curve. The symmetries of local motifs that can potentially emerge are not known a priori. Consequently, electronic responses unfiltered by artificial truncation are then required to embody the terms that tip the balance to the correct set of structures. Therefore, our fully responsive molecular model produces, a simple, accurate, and intuitive picture of water’s complexity and its molecular origin, predicting water’s signature physical properties from ice, through liquid–vapor coexistence, to the critical point.

CALCULATION FOR A Cu(001) SURFACE WITH AN IMPURITY ATOM

1999 ◽  
Vol 13 (04) ◽  
pp. 389-396
Author(s):  
CHIH-KAI YANG
Keyword(s):  
Electronic Structure ◽  
Impurity Atom ◽  
Magnetic Moments ◽  
Tight Binding ◽  
Real Space ◽  
Structure Calculation ◽  
Spin Polarized ◽  
Densities Of States ◽  
Self Consistent ◽  
Local Densities

I use a self-consistent electronic structure calculation to study the system of Cu(001) that has an impurity atom replacing one of the surface Cu atoms. The calculation makes use of the tight-binding linear muffin-tin orbitals (TB-LMTO) and is carried out in real space. I am able to derive the spin-polarized local densities of states for the impurity Cr and Fe respectively, which have peaks below the Fermi level. Charge transfers between the impurities and their neighbors also result in different distributions of magnetic moments for the two impurity systems, with the Cr having approximately 0.5μ B and the Fe atom having a negligible magnetic moment.

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