@article{TEXTUAL,
      recid = {10991},
      author = {Xiao, Jianwei and Yang, Huizhen and Wu, Xiaozhi and  Younus, Fatima and Li, Peng and Wen, Bin and Zhang, Xiangyi  and Wang, Yanbin and Tian, Yongjun},
      title = {Dislocation behaviors in nanotwinned diamond},
      journal = {Science Advances},
      address = {2018-09-21},
      number = {TEXTUAL},
      abstract = {Experimental results (Huang et al.) indicated that  nanotwinned diamond (nt-diamond) has unprecedented  hardness, whose physical mechanism has remained elusive. In  this report, we categorize interaction modes between  dislocations and twin planes in nt-diamond and calculate  the associated reaction heat, activation energies, and  barrier strength using molecular dynamics. On the basis of  the Sachs model, twin thickness dependence of nt-diamond  hardness is evaluated, which is in good agreement with the  experimental data. We show that two factors contribute to  the unusually high hardness of nt-diamond: high lattice  frictional stress by the nature of carbon bonding in  diamond and high athermal stress due to the Hall-Petch  effect. Both factors stem from the low activation volumes  and high activation energy for dislocation nucleation and  propagation in diamond twin planes. This work provides new  insights into hardening mechanisms in nt-diamond and will  be helpful for developing new superhard materials in the  future.},
      url = {http://knowledge.uchicago.edu/record/10991},
}