Investigation of the effects of boron on Ni3Al grain boundaries by atomistic simulations

1990 ◽  
Vol 5 (5) ◽  
pp. 955-970 ◽  
Author(s):  
S.P. Chen ◽  
A.F. Voter ◽  
R.C. Albers ◽  
A.M. Boring ◽  
P.J. Hay
Keyword(s):  
Grain Boundaries ◽  
Electronic Band Structure ◽  
Cohesive Strength ◽  
Atomistic Simulations ◽  
Electronic Band ◽  
Free Surfaces ◽  
Embedded Atom ◽  
Band Structure Calculations ◽  
Structure Calculations ◽  
Good Agreement

A series of simulations has been performed on grain boundaries in Ni and Ni3Al with and without boron doping using embedded atom-style potentials. A new procedure of obtaining “reference” data for boron related properties from electronic band structure calculations has been employed. Good agreement with existing experimental structural and energetic determinations was obtained. Boron is found to segregate more strongly to grain boundaries than to free surfaces. Adding boron to grain boundaries in Ni and Ni3Al increases their cohesive strength and the work required to pull apart the boundary. This effect is much more dramatic for Ni-rich boundaries than for stoichiometric or Al-rich boundaries. In some Ni-rich cases, adding boron increases the cohesive strength of the boundary to such an extent that the boundaries become stronger than the bulk. Bulk Ni3Al samples that are Ni-rich produce Ni-rich grain boundaries. The best cohesive properties of Ni3Al grain boundaries are obtained when the boundary is Ni saturated and also with boron present. Boron and nickel are found to cosegregate to the grain boundaries.

Atomistic Simulations of Interfaces in Metals and Alloys

1988 ◽  
Vol 141 ◽  
Author(s):  
S. P. Chen
Keyword(s):  
Thin Films ◽  
Electronic Band Structure ◽  
Atomistic Simulations ◽  
Electronic Band ◽  
Free Surfaces ◽  
Segregation Behavior ◽  
Embedded Atom ◽  
Band Structure Calculations ◽  
Structure Calculations ◽  
Good Agreement

AbstractWe have used embedded atom potentials to simulate the surfaces, thin films and grain boundaries in metals (Ni and Al) and alloys (NiAl and Ni3Al). The calculated surface relaxations and ripplings of free surfaces are in good agreement with experiments. A new interference phenomena of interlayer relaxation in thin films are observed in the simulation. The segregation behavior of B and S and their effects on the mechanical properties of Ni3Al are correctly predicted with potentials fitted to data obtained by electronic band structure calculations.

Ab Initio Electronic Structure Studies of CuO Multiferroics

2012 ◽  
Vol 488-489 ◽  
pp. 129-132 ◽  
Author(s):  
C. Kanagaraj ◽  
Baskaran Natesan
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Metallic State ◽  
Magnetic Ground State ◽  
Electronic Band ◽  
Functional Theory ◽  
High Tc ◽  
Band Structure Calculations ◽  
Structure Calculations

We have performed detailed structural, electronic and magnetic properties of high - TC multiferroic CuO using first principles density functional theory. The total energy results revealed that AFM is the most stable magnetic ground state of CuO. The DOS and electronic band structure calculations show that in the absence of on-site Coulomb interaction (U), AFM structure of CuO heads to a metallic state. However, upon incorporating U in the calculations, a band gap of 1.2 eV is recovered. Furthermore, the Born effective charges calculated on Cu does not show any anomalous character.This suggests that the polarization seen in CuO could be attributed to the spin induced AFM ordering effect.

Ab initio electronic band structure calculations of half-metallic c alcium pnictides

2007 ◽  
Vol 244 (12) ◽  
pp. 4643-4650 ◽  
Author(s):  
G. Jaiganesh ◽  
R. D. Eithiraj ◽  
G. Kalpana ◽  
M. Rajagopalan
Keyword(s):  
Band Structure ◽  
Ab Initio ◽  
Electronic Band Structure ◽  
Electronic Band ◽  
Half Metallic ◽  
Band Structure Calculations ◽  
Structure Calculations

Electronic Structures of P-Type Doped CuInS2

1996 ◽  
Vol 426 ◽  
Author(s):  
T. Yamamoto ◽  
H. Katayama-Yoshida
Keyword(s):  
Electronic Structures ◽  
Electronic Band Structure ◽  
Spherical Wave ◽  
Material Design ◽  
Electronic Band ◽  
Design Considerations ◽  
Band Structure Calculations ◽  
P Type ◽  
Structure Calculations ◽  
Codoping Method

AbstractWe have studied the electronic structures of CuIn(S0.875X0.125)2 (X=B, C, N, Si or P) based on the ab-initio electronic band structure calculations using the augmented spherical wave (ASW) method. We have clarified that the physical characteristics of the p-type doped CuInS2 crystals are mainly determined by a change in the strength of interactions between Cu and S atoms. On the basis of the calculated results, we discussed the material design considerations, such as controlling the strength of resistivity for p-type doped CulnS2 materials and converting the conduction type, from n-type to p-type by a codoping method.

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