An MD simulation to form an NV-N center using N-2 implantation into diamond

作者：Nakagawa Sachiko T^*; Nagao Hatsuki; Betz Gerhard

来源：Diamond and Related Materials, 2011, 20(7): 927-930.

DOI：10.1016/j.diamond.2011.05.008

• Diamond
• NV-N center
• Molecular dynamics simulation
• Molecular beam implantation
• Lateral range straggling

We have examined the dissociation process of a low-energy molecular beam making use of an empirical molecular dynamic simulation. The main concern was to explain why two (nitrogen molecule N-2) beams with different energy (sub-key and key) give a similar intrapair distance RN-N in diamond. It was due to the peculiar dependence of the lateral range straggling on the incident energy across a few keV. When a sub-keV (N-2) beam was implanted into a diamond, the dissociation elapsed a long time until it was settled in several hundreds fs because of multiple collisions. The range distribution caused by multiple collisions is almost isotropic whereas it becomes anisotropic when used a (N-2) beam with the higher energy than that. From the viewpoint of computation, a few key is a critical energy to choose an algorithm MD or MC with binary collision approximation. For the case of sub-key N-2 beam, MD is indispensable. This proved the reason of the apparent contradiction. Much later than the collision stage, a definite change further occurred in the long-range-order of the crystal at around 2 ps in diamond. It seems a phonon-assisted phenomenon would start then and might affect on the further events to be occurred later than 20 ps.

• 出版日期2011-7