کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1680509 | 1518667 | 2015 | 5 صفحه PDF | دانلود رایگان |
Using a first-principles method, we have investigated site preference and diffusion properties of carbon (C) in copper (Cu). A single C atom energetically prefers to occupy the octahedral interstitial site (OIS) instead of the tetrahedral interstitial site. Double C atoms tend to be paired up at the nearest neighboring OIS’s along the 〈1 0 0〉 direction mediated by a bridging Cu atom with a distance of 3.85 Å and a binding energy of 0.15 eV. This suggests that an indirectly attractive interaction between C atoms exists, which might lead to a local higher concentration of C in Cu. We demonstrate that the OIS → OIS path is the optimal diffusion path of C in Cu with diffusion barrier of 0.93 eV. By the estimation of pre-exponential factor according to a classical thermodynamics model, the diffusion coefficient as a function of temperature has been determined, which is 3.68 × 10−15 m2/s at a typical temperature of 600 K. The results provide a good reference to understand the behavior of C in Cu.
Journal: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms - Volume 352, 1 June 2015, Pages 72–76