1,721,271 research outputs found
A modified embedded atom method interatomic potential for silicon
No full textA semi-empirical interatomic potential for silicon has been developed, based on the modified embedded atom method formalism. This potential describes elastic, structural, point defect, surface, thermal (except melting point), and cluster properties as satisfactorily as any other empirical potential ever developed. When compared to the previously developed MEAM Si potential [M.I. Baskes, J.S. Nelson, A.F. Wright, Phys. Rev. B 40 (1989) 6085], for example, improvements were made in the description of surface relaxations, thermal expansion, and amorphous structure. This potential has the same formalism as already developed MEAM potentials for bcc, fcc, and hcp elements, and can be easily extended to describe various metal-silicon multi-component systems. (c) 2006 Elsevier Ltd. All rights reserved.11sciescopu
A modified embedded-atom method interatomic potential for the Fe-C system
No full textA modified embedded-atom method (MEAM) interatomic potential for the Fe-C binary system has been developed using previous MEAM potentials of Fe and C. The potential parameters were determined by fitting to experimental information on the dilute heat of solution of carbon, the vacancy-carbon binding energy and its configuration, the location of interstitial carbon atoms and the migration energy of carbon atoms in body-centered cubic (bcc) Fe, and to a first-principles calculation result for the cohesive energy of a hypothetical NaCl-type FeC. The potential reproduces the known physical properties of carbon as an interstitial solute element in bcc Fe and face-centered cubic Fe very well. The applicability of this potential to atomistic approaches for investigating interactions between carbon interstitial solute atoms and other defects such as vacancies, dislocations and grain boundaries, and also for investigating the effects of carbon on various deformation and mechanical behaviors of iron is demonstrated. (c) 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.11sciescopu
Computation of grain boundary energies
No full textA new method of computing grain boundary energies for arbitrary misorientation and inclination angles has been proposed, based on an atomistic approach (molecular statics) using a semi-empirical atomic potential (2NN MEAM). The procedure was applied to computation of the [ 110] symmetric tilt boundary energy of pure Al. It is shown that the computed grain boundary energy and especially its misorientation dependence are in good agreement with the information in the experimental literature. The probable sources and amounts of computation error and the applicability to the computation of inter-phase interface boundary energy are also discussed.11sciescopu
Modified embedded-atom method interatomic potentials for the Fe-Nb and Fe-Ti binary systems
No full textA semi-empirical interatomic potential formalism, the second-nearest-neighbor modified embedded-atom method (2NN MEAM), has been applied to obtain interatomic potentials for Fe-Nb and Fe-Ti systems based on the previously developed potentials for pure Fe, Nb and Ti. The present potentials generally reproduce the fundamental physical properties of the Fe-Nb and Fe-Ti systems accurately. The potentials can be easily combined with already-developed MEAM potentials for binary carbide or nitride systems and can be used to describe Fe-(Ti,Nb)-(C,N) multicomponent systems. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.11sciescopu
Modified embedded-atom method interatomic potentials for pure Y and the V-Pd-Y ternary system
No full textInteratomic potentials for pure Y and the V-Pd-Y ternary system have been developed on the basis of the second nearest-neighbor modified embedded-atom method (2NN MEAM) formalism, with a purpose of investigating the interdiffusion mechanism and the role of yttrium in the palladium-coated vanadium-based hydrogen separation membranes. The potentials can describe various fundamental physical properties of pure Y (the bulk, defect and thermal properties) and the alloy behaviors (structural, thermodynamic and defect properties of solid solutions and compounds) of constituent systems in reasonable agreement with experimental data or first-principles calculations.11sciescopu
A modified embedded atom method interatomic potential for carbon
No full textA semi-empirical interatomic potential for carbon has been developed, based on the modified embedded atom method formalism. The potential describes the structural properties of various polytypes of carbon, elastic, defect and surface properties of diamonds as satisfactorily as the well-known Tersoff potential. Combined with the Lennard-Jones potential, it can also reproduce the physical properties of graphite and amorphous carbon reasonably well. The applicability of the present potential to atomistic approaches on carbon nanotubes and fullerenes is also shown. The potential has the same formalism as previously developed MEAM potentials for bcc, fcc and hcp elements, and can be easily extended to describe various metal-carbon alloy systems. (c) 2005 Elsevier Ltd. All rights reserved.11sciescopu
A modified embedded-atom method interatomic potential for the Cu-Zr system
No full textA modified embedded-atom method (MEAM) interatomic potential for the Cu-Zr system has been developed based on the previously developed MEAM potentials for pure Cu and Zr. The potential describes fundamental physical properties and alloy behavior of the Cu-Zr binary system reasonably well. The applicability of the potential to atomistic investigations of mechanical and deformation behavior for the Cu-Zr binary and Cu-Zr-based multicomponent amorphous alloys is also demonstrated by showing that fully relaxed and realistic amorphous structures can be generated by molecular dynamics simulations.11sciescopu
Modified embedded-atom method interatomic potentials for the Ti-C and Ti-N binary systems
No full textModified embedded-atom method (MEAM) interatomic potentials for the Ti-C and Ti-N binary systems have been developed using previously developed MEAM potentials of Ti, C and N. The potential parameters were determined by fitting to experimental data on the enthalpy of formation, lattice parameter, elastic constants, thermal linear expansion of NaCl-type TiC and TiN, and dilute heat of solution of carbon and nitrogen atoms in hexagonal close-packed Ti. The potentials can describe fundamental physical properties (structural, elastic, thermal and surface properties) of the alloys well, in good agreement with experimental information or first-principles calculations. The applicability of the potentials to atomistic investigations of interactions between TiC or TiN precipitates and matrix, dislocations or other defects, and their effects on deformation and mechanical behaviors of metallic alloys is discussed. (c) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.11sciescopu
A modified embedded-atom method interatomic potential for the Fe-H system
No full textA modified embedded-atom method (MEAM) interatomic potential for the Fe-H binary system has been developed using previously developed MEAM potentials of Fe and H. The potential parameters were determined by fitting to experimental data on the dilute heat of solution of hydrogen in body-centered cubic (bcc) and face-centered cubic (fcc) Fe, the vacancy-hydrogen binding energy in bcc Fe, and to a first-principles calculation for the lattice parameter and bulk modulus of a hypothetical NaCl-type FeH. The potential accurately reproduces the known physical properties of hydrogen as an interstitial solute element in bee and fcc Fe. The applicability of the potential to atomistic approaches for investigating interactions between hydrogen atoms and other defects such as vacancies, dislocations and grain boundaries, and also for investigating the effects of hydrogen on various deformation and mechanical behaviors of iron is demonstrated. (c) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.11sciescopu
Origin of unrealistic blunting during atomistic fracture simulations based on MEAM potentials
No full textAtomistic simulations based on interatomic potentials have frequently failed to correctly reproduce the brittle fracture of materials, showing an unrealistic blunting. We analyse the origin of the unrealistic blunting during atomistic simulations by modified embedded-atom method (MEAM) potentials for experimentally well-known brittle materials such as bcc tungsten and diamond silicon. The radial cut-off which has been thought to give no influence on MEAM calculations is found to have a decisive effect on the crack propagation behaviour. Extending both cut-off distance and truncation range can prevent the unrealistic blunting, reproducing many well-known fracture behaviour which have been difficult to reproduce. The result provides a guideline for future atomistic simulations that focus on various fracture-related phenomena including the failure of metallic-covalent bonding material systems using MEAM potentials.11sciescopu
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