Ab Initio Electronic Structure Calculations of the Σ 5 (210) [001] Tilt Grain Boundary in Ni3Al

1997 ◽  
Vol 472 ◽  
Author(s):  
Gang Lu ◽  
Nicholas Kioussis
Keyword(s):  
Electronic Structure ◽  
Grain Boundary ◽  
Boundary Energy ◽  
Boundary Region ◽  
Embedded Atom Method ◽  
Full Potential ◽  
Plane Wave Method ◽  
Embedded Atom ◽  
Tilt Grain Boundary ◽  
Linearized Augmented Plane Wave

ABSTRACTThe atomic and the electronic structure of the Σ 5 (210) [001] tilt grain boundary in Ni3Al have been calculated using the full potential linearized-augmented plane-wave method. The strain field normal to the boundary plane and the excess grain boundary volume are calculated and compared with the results obtained using the embedded-atom method (EAM). The interlayer strain normal to the grain boundary oscillates with increasing distance from the grain boundary. The bonding charge distributions suggest that bonding in the boundary region is significantly different from that in the bulk. The grain boundary energy and the Griffith cohesive energy are calculated and compared with the EAM results.

First Principle Study on Electronic Structure of Nanocrystalline BaTiO3 Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 2510-2512
Author(s):  
Xiang Yun Deng ◽  
Long Tu Li ◽  
Xiao Hui Wang ◽  
Zhi Lun Gui
Keyword(s):  
Electronic Structure ◽  
Partial Density ◽  
Full Potential ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Generalized Gradient Approximation ◽  
Augmented Plane Wave Method ◽  
Nanocrystalline Batio3 Ceramics ◽  
Linearized Augmented Plane Wave

The full potential linearized augmented plane wave method within the generalized gradient approximation was used to calculate electronic structure of nanocrystalline BaTiO3 ceramics. We calculated the total and partial density of states of 50 nm BaTiO3 ceramics. The results show that the atoms distribution of nanograin BaTiO3 ceramics is different from those of coarse BaTiO3 ceramics. It is also revealed that the hybridization between Ti 3d and O 2p is very strong, which is very important to the ferroelectric stability of nanocrystalline BaTiO3 ceramics.

ALL-ELECTRON LOCAL-DENSITY DETERMINATION OF THE ELECTRONIC STRUCTURE AND SURFACE ENERGY OF ZR(0001)

1993 ◽  
Vol 07 (01n03) ◽  
pp. 520-523
Author(s):  
J. I. LEE ◽  
S. K. HWANG ◽  
S. C. HONG ◽  
A. J. FREEMAN
Keyword(s):  
Electronic Structure ◽  
Surface Energy ◽  
Density Functional ◽  
Local Density ◽  
Full Potential ◽  
Functional Theory ◽  
Plane Wave Method ◽  
Local Density Functional Theory ◽  
Linearized Augmented Plane Wave

The electronic structure and surface energy of Zr(0001) is determined theoretically using the all-electron full-potential linearized augmented plane wave method based on local-density functional theory. We found the value of surface energy to be 1.6 J/m 2 which is comparable to the value estimated from experiments on liquid zirconium at the melting point. It is, however, much smaller than the surface energies of W(001), V(001) and bcc Co(001). The calculated valence charge density, workfunction, and layer projected density of states for Zr(0001) are also presented.

Atomistic Simulation of Grain Boundaries of the Twin Limited Structure in Ni3Al

1994 ◽  
Vol 364 ◽  
Author(s):  
Maria-Lynn Turi ◽  
R. Zugic ◽  
B. Szpunar ◽  
U. Erb ◽  
G. Palumbo ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Atomistic Simulation ◽  
Boundary Energy ◽  
Boundary Plane ◽  
Embedded Atom Method ◽  
Grain Boundary Energy ◽  
Embedded Atom ◽  
Grain Boundary Plane ◽  
Dynamics Simulations

AbstractEmbedded atom method molecular dynamics simulations of low Σ grain boundaries in Ni3Al are presented. The results show that the grain boundary plane has a larger effect on grain boundary energy than the Σ value, rigid body translations and stoichiometry. Assessment of the energies of Σ3n (n ≥ 1) grain boundaries in Ni3Al for various grain boundary planes indicates that only the Σ3 grain boundary is energetically preferred. The implications of this result for the development of the twin limited structure based on energetic considerations are discussed.

Electronic Structure Of (AgSb)xPbn-2xTen

2003 ◽  
Vol 793 ◽  
Author(s):  
Daniel I Bilc ◽  
S.D. Mahanti ◽  
M.G. Kanatzidis
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Density Functional ◽  
Full Potential ◽  
Generalized Gradient ◽  
Two Component System ◽  
Functional Theory ◽  
Covalent Interaction ◽  
Salt Structure ◽  
Linearized Augmented Plane Wave

ABSTRACTComplex quaternary chalcogenides (AgSb)xPbn-2xTen (0<x<n/2) are thought to be narrow band-gap semiconductors which are very good candidates for room and high temperature thermoelectric applications. These systems form in the rock-salt structure similar to the well known two component system PbTe (x=0). In these systems Ag and Sb occupy Pb sites randomly although there is some evidence of short-range order. To gain insights into the electronic structure of these compounds, we have performed electronic structure calculations in AgSbTe2 (x=n/2). These calculations were carried out within ab initio density functional theory (DFT) using full potential linearized augmented plane wave (LAPW) method. The generalized gradient approximation (GGA) was used to treat the exchange and correlation potential. Spinorbit interaction (SOI) was incorporated using a second variational procedure. Since it is difficult to treat disorder in ab initio calculations, we have used several ordered structures for AgSbTe2. All these structures show semimetallic behavior with a pseudogap near the Fermi energy. Te and Sb p orbitals, which are close in energy, hybridize rather strongly indicating a covalent interaction between Te and Sb atoms.

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