Nanoscale engineering of radiation tolerant silicon carbide.

Radiation tolerance is determined by how effectively the microstructure can remove point defects produced by irradiation. Engineered nanocrystalline SiC with a high-density of stacking faults (SFs) has significantly enhanced recombination of interstitials and vacancies, leading to self-healing of irradiation-induced defects. While single crystal SiC readily undergoes an irradiation-induced crystalline to amorphous transformation at room temperature, the nano-engineered SiC with a high-density of SFs exhibits more than an order of magnitude increase in radiation resistance. Molecular dynamics simulations of collision cascades show that the nano-layered SFs lead to enhanced mobility of interstitial Si atoms. The remarkable radiation resistance in the nano-engineered SiC is attributed to the high-density of SFs within nano-sized grain structures that significantly enhance point defect annihilation.

[1]  D. Morgan,et al.  Effects of grain size and grain boundaries on defect production in nanocrystalline 3C–SiC , 2010 .

[2]  W. Tredway.  Toughened Ceramics , 1998, Science.

[3]  Y. Katoh,et al.  Analysis of grain boundary sinks and interstitial diffusion in neutron-irradiated SiC , 2011 .

[4]  W. J. Weber,et al.  Grain Growth and Phase Stability of Nanocrystalline Cubic Zirconia under Ion Irradiation , 2010 .

[5]  W. Weber,et al.  Response of nanocrystalline 3C silicon carbide to heavy-ion irradiation , 2009 .

[6]  W. J. Weber,et al.  Damage profile and ion distribution of slow heavy ions in compounds , 2009 .

[7]  Lyndon Edwards,et al.  Greater tolerance for nuclear materials. , 2008, Nature materials.

[8]  Noam Bernstein,et al.  Thermal effects in 10 keV Si PKA cascades in 3C-SiC , 2009 .

[9]  M. Shiga,et al.  Rapid estimation of elastic constants by molecular dynamics simulation under constant stress , 2004 .

[10]  W. J. Weber,et al.  Radiation effects in SiC for nuclear structural applications , 2012 .

[11]  M. Demkowicz,et al.  The radiation damage tolerance of ultra-high strength nanolayered composites , 2007 .

[12]  Y. Katoh,et al.  Handbook of SiC properties for fuel performance modeling , 2007 .

[13]  W. Weber,et al.  The temperature dependence of ion-beam-induced amorphization in β-SiC , 1995 .

[14]  K. Lim,et al.  Nanocrystalline silicon carbide films for solar photovoltaics: The role of dangling-bond defects , 2008 .

[15]  S. Zinkle,et al.  Structural materials for fission & fusion energy , 2009 .

[16]  Bob B. Buckley,et al.  Room temperature coherent control of defect spin qubits in silicon carbide , 2011, Nature.

[17]  V. Krstić,et al.  Silicon carbide as an inert-matrix for a thermal reactor fuel , 1999 .

[18]  G. Ackland.  Controlling Radiation Damage , 2010, Science.

[19]  R. Devanathan,et al.  The efficiency of damage production in silicon carbide , 2004 .

[20]  F. Gao,et al.  Primary damage states produced by Si and Au recoils in SiC: A molecular dynamics and experimental investigation , 2001 .

[21]  M. Mehregany,et al.  Electromechanical Computing at 500°C with Silicon Carbide , 2010, Science.

[22]  William J. Weber,et al.  Displacement threshold energies in β-SiC , 1998 .

[23]  N. Yu,et al.  Irradiation-induced amorphization in β-SiC , 1998 .

[24]  Priya Vashishta,et al.  A Crossover in the Mechanical Response of Nanocrystalline Ceramics , 2005, Science.

[25]  M. Kovalenko,et al.  Colloidal Nanocrystals with Molecular Metal Chalcogenide Surface Ligands , 2009, Science.

[26]  C. Eddy,et al.  Silicon Carbide as a Platform for Power Electronics , 2009, Science.

[27]  L. Snead,et al.  Near-surface and bulk behavior of Ag in SiC , 2012 .

[28]  W. J. Weber,et al.  Empirical potential approach for defect properties in 3C-SiC , 2002 .

[29]  William J. Weber,et al.  Energy dissipation and defect generation in nanocrystalline silicon carbide , 2010 .

[30]  Neil B. Morley,et al.  Design requirements for SiC/SiC composites structural material in fusion power reactor blankets , 1998 .

[31]  William J. Weber,et al.  Models and mechanisms of irradiation-induced amorphization in ceramics , 2000 .

[32]  Feng Liao,et al.  Superhard nanocrystalline silicon carbide films , 2005 .

[33]  F. Namavar,et al.  Structural modification of nanocrystalline ceria by ion beams. , 2011, Physical chemistry chemical physics : PCCP.

[34]  Blas P. Uberuaga,et al.  Efficient Annealing of Radiation Damage Near Grain Boundaries via Interstitial Emission , 2010, Science.

[35]  W. Weber,et al.  Amorphization of nanocrystalline 3C−SiC irradiated with Si^+ ions , 2010 .

[36]  A. Hallén,et al.  Effects of implantation temperature on damage accumulation in Al-implanted 4H-SiC , 2004 .

[37]  Steven J. Zinkle,et al.  Amorphization of SiC under ion and neutron irradiation , 1998 .

[38]  W. J. Weber,et al.  Response of Strontium Titanate to Ion and Electron Irradiation , 2009 .

[39]  Bernhard Gutmann,et al.  Microwave chemistry in silicon carbide reaction vials: separating thermal from nonthermal effects. , 2009, Angewandte Chemie.

[40]  A Hirata,et al.  Atomic structure of nanoclusters in oxide-dispersion-strengthened steels. , 2011, Nature materials.