Self-interstitial clusters in radiation damage accumulation: coupled molecular dynamics and metadynamics simulations

Self-interstitial interactions causing volume expansion in bcc Fe are studied through an idealized microstructure evolution model in which only self-interstial atoms (SIAs) are inserted. Using a combination of non-equilibrium molecular dynamics simulations and a metadynamics algorithm, meta-stable SIA clusters are observed to nucleate and grow into dislocation loops or localized amorphous phases, both contributing to swelling behavior persisting well beyond the atomistic time scale. A non-monotonic local density variation with dose rate is found and attributed to competing evolutions of different defective structures.

[1]  Ju Li,et al.  AtomEye: an efficient atomistic configuration viewer , 2003 .

[2]  F. Garner,et al.  Factors which determine the swelling behavior of austenitic stainless steels , 1984 .

[3]  S. Valeri,et al.  Focused ion beam induced swelling in MgO(001) , 2006 .

[4]  Toshihiko Satō,et al.  The primary origin of dose rate effects on microstructural evolution of austenitic alloys during neutron irradiation , 2002 .

[5]  D. Gelles.  Void swelling in binary FeCr alloys at 200 dpa , 1995 .

[6]  Mark T. Robinson,et al.  Basic physics of radiation damage production , 1994 .

[7]  A. Vehanen,et al.  Vacancies and carbon impurities inα- iron: Electron irradiation , 1982 .

[8]  W. G. Wolfer,et al.  Vacancy cluster evolution and swelling in irradiated 316 stainless steel , 2004 .

[9]  Graeme Ackland,et al.  Development of an interatomic potential for phosphorus impurities in α-iron , 2004 .

[10]  A. Laio,et al.  Metadynamics: a method to simulate rare events and reconstruct the free energy in biophysics, chemistry and material science , 2008 .

[11]  Y. Limoge,et al.  Amorphization mechanism in metallic crystalline solids under irradiation , 1984 .

[12]  B. Yildiz,et al.  Unfaulting mechanism of trapped self-interstitial atom clusters in bcc Fe: A kinetic study based on the potential energy landscape , 2010 .

[13]  Sidney Yip,et al.  Computing the viscosity of supercooled liquids. , 2009, The Journal of chemical physics.

[14]  M. Caturla,et al.  Recrystallization of a planar amorphous‐crystalline interface in silicon by low energy recoils: A molecular dynamics study , 1995 .

[15]  L. Mansur.  Theory and experimental background on dimensional changes in irradiated alloys , 1994 .

[16]  Yip,et al.  Defect-induced crystal-to-amorphous transition in an atomistic simulation model. , 1987, Physical review letters.

[17]  E. J. Fulton,et al.  Voids in Irradiated Stainless Steel , 1967, Nature.

[18]  Aneesur Rahman,et al.  Computer simulation studies of radiation induced amorphization , 1988 .

[19]  J. Keinonen,et al.  Amorphization mechanism and defect structures in ion-beam-amorphized Si, Ge, and GaAs , 2002 .

[20]  Wilhelm G. Wolfer,et al.  Void nucleation, growth, and coalescence in irradiated metals , 2008, 0803.3829.

[21]  A. Laio,et al.  Escaping free-energy minima , 2002, Proceedings of the National Academy of Sciences of the United States of America.