Embedded - Atom - Method Interatomic Potentials for BCC - Iron

ABSTRACTAn embedded-atom-method (EAM) interatomic potential [1] for bcc-iron is derived. It is fitted exactly to the lattice parameter, elastic constants, an approximation to the unrelaxed vacancy formation energy, and Rose's expression for the cohesive energy [2]. Formation energies and relaxation volumes of point defects are calculated. We find that the relative energies of the defect configurations depend on the functional fitting details of the potential considered, mainly its range: the experimental interstitial configuration of lowest energy can be reproduced by changing this parameter. This result is confirmed by calculating the same defect energies using other EAM potentials, based on the ones developed by Harrison et al. [3].

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Modified embedded-atom method interatomic potential for the Fe–Pt alloy system

Journal of Materials Research ◽

10.1557/jmr.2006.0008 ◽

2006 ◽

Vol 21 (1) ◽

pp. 199-208 ◽

Cited By ~ 26

Author(s):

Jaesong Kim ◽

Yangmo Koo ◽

Byeong-Joo Lee

Keyword(s):

Interatomic Potential ◽

Structural Evolution ◽

Alloy System ◽

Lattice Parameter ◽

Experimental Information ◽

Embedded Atom Method ◽

Present Calculation ◽

Embedded Atom ◽

Pt Alloy ◽

Modified Embedded Atom Method

A semi-empirical interatomic potential formalism, the modified embedded atom method (MEAM), has been applied to obtain an interatomic potential for the Fe–Pt alloy system, based on the previously developed potentials for pure Fe and Pt. The potential can describe basic physical properties of the alloys (lattice parameter, bulk modulus, stability of individual phases, and order/disorder transformations), in good agreement with experimental information. The procedure for the determination of potential parameter values and comparisons between the present calculation and experimental data or high level calculation are presented. The applicability of the potential to atomistic studies to investigate structural evolution of Fe50Pt50 alloy thin films during post-annealing is also discussed.

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Lattice Trapping of Cracks in Fe Using an Interatomic Potential Derived from Experimental Data and Ab Initio Calculations

MRS Proceedings ◽

10.1557/proc-653-z6.4 ◽

2000 ◽

Vol 653 ◽

Author(s):

D. Farkas ◽

M. J. Mehl ◽

D. A. Papaconstantopoulos

Keyword(s):

Experimental Data ◽

Interatomic Potential ◽

Interatomic Potentials ◽

Coordination Numbers ◽

Embedded Atom ◽

Recent Approach ◽

Basic Equilibrium ◽

Stability Of Structures ◽

Formation Energies ◽

Trapping Effects

AbstractA recent approach which combines first-principles and experimental data to produce highly accurate and reliable interatomic potentials is tested for the case of bcc and fcc Fe. The Embedded-Atom-like potential accurately reproduces the basic equilibrium properties of bcc Fe, including elastic constants, phonon properties, and vacancy formation energies, as well as the correct relative stability of structures with coordination numbers ranging from 12 to 4. This potential was used in a simulation study of lattice trapping effects during the cleavage fracture of bcc Fe. A strong directional anisotropy for crack propagation was observed due to lattice trapping effects. The strongest trapping effects were observed for cleavage along the {110} planes and it was found that lattice trapping strongly favors cleavage along the {100} planes.

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An interatomic potential for saturated hydrocarbons based on the modified embedded-atom method

Physical Chemistry Chemical Physics ◽

10.1039/c4cp00027g ◽

2014 ◽

Vol 16 (13) ◽

pp. 6233-6249 ◽

Cited By ~ 31

Author(s):

S. Nouranian ◽

M. A. Tschopp ◽

S. R. Gwaltney ◽

M. I. Baskes ◽

M. F. Horstemeyer

Keyword(s):

Interatomic Potential ◽

Embedded Atom Method ◽

Computationally Efficient ◽

Saturated Hydrocarbons ◽

Embedded Atom ◽

Modified Embedded Atom Method

Extension of the computationally efficient modified embedded-atom method to hydrocarbons and polymers.

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Modified embedded-atom method interatomic potential for theFe−Cualloy system and cascade simulations on pure Fe andFe−Cualloys

Physical Review B ◽

10.1103/physrevb.71.184205 ◽

2005 ◽

Vol 71 (18) ◽

Cited By ~ 40

Author(s):

Byeong-Joo Lee ◽

Brian D. Wirth ◽

Jae-Hyeok Shim ◽

Junhyun Kwon ◽

Sang Chul Kwon ◽

...

Keyword(s):

Interatomic Potential ◽

Embedded Atom Method ◽

Embedded Atom ◽

Modified Embedded Atom Method

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An embedded-atom method interatomic potential for Pd–H alloys

Journal of Materials Research ◽

10.1557/jmr.2008.0090 ◽

2008 ◽

Vol 23 (3) ◽

pp. 704-718 ◽

Cited By ~ 57

Author(s):

X.W. Zhou ◽

J.A. Zimmerman ◽

B.M. Wong ◽

J.J. Hoyt

Keyword(s):

Computational Models ◽

Mechanical Response ◽

Hydrogen Diffusion ◽

Interatomic Potential ◽

Diffusion Mechanism ◽

Miscibility Gap ◽

Embedded Atom Method ◽

Embedded Atom ◽

Formidable Challenge ◽

Embedded Atom Method Potential

Palladium hydrides have important applications. However, the complex Pd–H alloy system presents a formidable challenge to developing accurate computational models. In particular, the separation of a Pd–H system to dilute (α) and concentrated (β) phases is a central phenomenon, but the capability of interatomic potentials to display this phase miscibility gap has been lacking. We have extended an existing palladium embedded-atom method potential to construct a new Pd–H embedded-atom method potential by normalizing the elemental embedding energy and electron density functions. The developed Pd–H potential reasonably well predicts the lattice constants, cohesive energies, and elastic constants for palladium, hydrogen, and PdHx phases with a variety of compositions. It ensures the correct hydrogen interstitial sites within the hydrides and predicts the phase miscibility gap. Preliminary molecular dynamics simulations using this potential show the correct phase stability, hydrogen diffusion mechanism, and mechanical response of the Pd–H system.

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Structure and Elastic Properties of Ni/Cu and Ni/Au Multilayers

MRS Proceedings ◽

10.1557/proc-291-479 ◽

1992 ◽

Vol 291 ◽

Cited By ~ 1

Author(s):

Ademola Taiwo ◽

Hong Yan ◽

Gretchen Kalonji

Keyword(s):

Phase Transformation ◽

Elastic Properties ◽

Embedded Atom Method ◽

Interatomic Potentials ◽

Multilayer Systems ◽

Lattice Statics ◽

Embedded Atom ◽

Hcp Structure ◽

Fcc Structure ◽

Coherent Interfaces

ABSTRACTThe structure and elastic properties of Ni/Cu and Ni/Au multilayer systems are investigated as a function of the number of Ni monolayers built into the systems. We employed lattice statics simulations with the interatomic potentials described by the embedded-atom method. For the Ni/Cu systems, coherent interfaces and FCC structure are maintained, and no elastic anomaly is found. For the Ni/Au systems, when the Ni layers are thick enough, they undergo a strain-induced phase transformation from FCC to HCP structure. An enhancement of Young’s modulus of these systems is found to be associated with this structural change.

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First Principles Calculations of Defects in Unstable Crystals: Austenitic Iron

MRS Proceedings ◽

10.1557/opl.2011.1383 ◽

2011 ◽

Vol 1363 ◽

Cited By ~ 1

Author(s):

G.J. Ackland ◽

T.P.C. Klaver ◽

D.J. Hepburn

Keyword(s):

Point Defects ◽

First Principles ◽

Defect Formation ◽

Single Layer ◽

Temperature Limit ◽

Reference State ◽

First Principles Calculations ◽

General Picture ◽

Bcc Iron ◽

Defect Energies

ABSTRACTFirst principles calculations have given a new insight into the energies of point defects in many different materials, information which cannot be readily obtained from experiment. Most such calculations are done at zero Kelvin, with the assumption that finite temperature effects on defect energies and barriers are small. In some materials, however, the stable crystal structure of interest is mechanically unstable at 0K. In such cases, alternate approaches are needed. Here we present results of first principles calculations of austenitic iron using the VASP code. We determine an appropriate reference state for collinear magnetism to be the antiferromagnetic (001) double-layer (AFM-d) which is both stable and lower in energy than other possible models for the low temperature limit of paramagnetic fcc iron. Another plausible reference state is the antiferromagnetic (001) single layer (AFM-1). We then consider the energetics of dissolving typical alloying impurities (Ni, Cr) in the materials, and their interaction with point defects typical of the irradiated environment. We show that the calculated defect formation energies have fairly high dependence on the reference state chosen: in some cases this is due to instability of the reference state, a problem which does not seem to apply to AFM-d and AFM-1. Furthermore, there is a correlation between local free volume magnetism and energetics. Despite this, a general picture emerge that point defects in austenitic iron have geometries similar to those in simpler, non-magnetic, thermodynamically stable FCC metals. The defect energies are similar to those in BCC iron. The effect of substitutional Ni and Cr on defect properties is weak, rarely more than tenths of eV, so it is unlikely that small amounts of Ni and Cr will have a significant effect on the radiation damage in austenitic iron at high temperatures.

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