A modified W–W interatomic potential based on ab initio calculations

In this paper we have developed a Finnis–Sinclair-type interatomic potential for W–W interactions that is based on ab initio calculations. The modified potential is able to reproduce the correct formation energies of self-interstitial atom (SIA) defects in tungsten, offering a significant improvement over the Ackland–Thetford tungsten potential. Using the modified potential, the thermal expansion is calculated in a temperature range from 0 to 3500 K. The results are in reasonable agreement with the experimental data, thus overcoming the shortcomings of the negative thermal expansion using the Derlet–Nguyen–Manh–Dudarev tungsten potential. The W–W potential presented here is also applied to study in detail the diffusion of SIAs in tungsten. We reveal that the initial SIA initiates a sequence of tungsten atom displacements and replacements in the 〈1 1 1〉 direction. An Arrhenius fit to the diffusion data at temperatures below 550 K indicates a migration energy of 0.022 eV, which is in reasonable agreement with the experimental data.

[1]  Jun Wang,et al.  Radiation damage of tungsten surfaces by low energy helium atom bombardment – A molecular dynamics study , 2013 .

[2]  Jun Wang,et al.  Atomistic simulations of helium behavior in tungsten crystals , 2012 .

[3]  T. Ahlgren,et al.  Bond-order potential for point and extended defect simulations in tungsten , 2010 .

[4]  R. Gröger,et al.  Directional versus central-force bonding in studies of the structure and glide of 1/2⟨111⟩ screw dislocations in bcc transition metals , 2009 .

[5]  S.L. Dudarev,et al.  The non-degenerate core structure of a ½⟨111⟩ screw dislocation in bcc transition metals modelled using Finnis–Sinclair potentials: The necessary and sufficient conditions , 2009 .

[6]  R. Schäublin,et al.  Atomistic simulations of nanometric dislocation loops in bcc tungsten , 2009 .

[7]  C. Domain,et al.  An object Kinetic Monte Carlo Simulation of the dynamics of helium and point defects in tungsten , 2009 .

[8]  V. Vítek,et al.  Multiscale modeling of plastic deformation of molybdenum and tungsten: I. Atomistic studies of the core structure and glide of 1/2〈1 1 1〉 screw dislocations at 0 K , 2008, 0807.2667.

[9]  Peter M. Derlet,et al.  Multiscale modeling of crowdion and vacancy defects in body-centered-cubic transition metals , 2007 .

[10]  Christian Elsässer,et al.  Bond-Order Potential for Simulations of Extended Defects in Tungsten , 2007 .

[11]  C. Domain,et al.  Ab initio calculations about intrinsic point defects and He in W , 2007 .

[12]  R. Schäublin,et al.  Molecular dynamics simulation of radiation damage in bcc tungsten , 2007 .

[13]  C. Domain,et al.  Migration energy of He in W revisited by ab initio calculations. , 2006, Physical review letters.

[14]  X. Dai,et al.  Extended Finnis–Sinclair potential for bcc and fcc metals and alloys , 2006 .

[15]  Kai Nordlund,et al.  Analytical interatomic potential for modeling nonequilibrium processes in the W–C–H system , 2005 .

[16]  R. Neu,et al.  Materials for plasma facing components of fusion reactors , 2004 .

[17]  David G. Pettifor,et al.  Bond-order potential for molybdenum: Application to dislocation behavior , 2004 .

[18]  K. Jacobsen,et al.  Density functional theory studies of screw dislocation core structures in bcc metals , 2003 .

[19]  Michael I. Baskes,et al.  Second nearest-neighbor modified embedded atom method potentials for bcc transition metals , 2001 .

[20]  P. Steadman,et al.  Interlayer relaxation of W(110) studied by surface X-ray diffraction , 2001 .

[21]  G. Janeschitz.  Plasma–wall interaction issues in ITER , 2001 .

[22]  B. Meyer,et al.  Symmetrical tilt grain boundaries in body-centred cubic transition metals: An ab initio local-density-functional study , 2000 .

[23]  A. Hartmaier,et al.  Controlling factors for the brittle-to-ductile transition in tungsten single crystals , 1998, Science.

[24]  J. Kollár,et al.  The surface energy of metals , 1998 .

[25]  Robert R. Reeber,et al.  The role of defects on thermophysical properties : thermal expansion of V, Nb, Ta, Mo and W , 1998 .

[26]  Stefano de Gironcoli,et al.  Vacancy self-diffusion parameters in tungsten: Finite electron-temperature LDA calculations , 1998 .

[27]  V. Vítek,et al.  Plastic anisotropy in b.c.c. transition metals , 1998 .

[28]  G. White,et al.  Thermophysical properties of some key solids: An update , 1997 .

[29]  V. Ozoliņš,et al.  PHONON INSTABILITIES IN FCC AND BCC TUNGSTEN , 1997 .

[30]  L. Hammer,et al.  Hydrogen on W(110): an adsorption structure revisited , 1997 .

[31]  M. S. Singh,et al.  Equilibrium geometry and electronic structure of the low-temperature W(001) surface. , 1992, Physical review. B, Condensed matter.

[32]  Shi,et al.  Time-of-flight scattering and recoiling spectrometry. I. Structure of the W(211) surface. , 1989, Physical review. B, Condensed matter.

[33]  Robinson,et al.  Multilayer reconstruction of the W(001) surface. , 1988, Physical review. B, Condensed matter.

[34]  Fu,et al.  Multilayer reconstruction and vibrational properties of W(001). , 1988, Physical review. B, Condensed matter.

[35]  G. Ackland,et al.  An improved N-body semi-empirical model for body-centred cubic transition metals , 1987 .

[36]  J. Mundy,et al.  Vacancy Migration Enthalpy in Tungsten at High Temperatures , 1987 .

[37]  C Gough,et al.  Introduction to Solid State Physics (6th edn) , 1986 .

[38]  D. Seidman,et al.  Diffusivity of 3He atoms in perfect tungsten crystals , 1984 .

[39]  M. Finnis,et al.  A simple empirical N-body potential for transition metals , 1984 .

[40]  M. Baskes,et al.  Embedded-atom method: Derivation and application to impurities, surfaces, and other defects in metals , 1984 .

[41]  J. Christian.  Some surprising features of the plastic deformation of body-centered cubic metals and alloys , 1983 .

[42]  H. Schaefer,et al.  High–temperature positron annihilation and vacancy formation in refractory metals , 1979 .

[43]  R. Balluffi.  Vacancy defect mobilities and binding energies obtained from annealing studies , 1976 .

[44]  F. Dausinger,et al.  Long-Range Migration of Self-Interstitial Atoms in Tungsten , 1975 .

[45]  M. Stowell,et al.  Handbook of Chemistry and Physics 50th Edn , 1970 .

[46]  D. I. Bolef,et al.  Elastic Constants of Single‐Crystal Mo and W between 77° and 500°K , 1962 .

[47]  C. Kittel.  Introduction to solid state physics , 1954 .

[48]  Brian D. Wirth,et al.  Interatomic potentials for simulation of He bubble formation in W , 2013 .

[49]  G. Lu,et al.  Modified analytical interatomic potential for a W–H system with defects , 2011 .

[50]  Andrew P. Horsfield,et al.  Self-interstitial atom defects in bcc transition metals: Group-specific trends , 2006 .

[51]  G. Taylor.  Thermally-activated deformation of BCC metals and alloys , 1992 .