Abstract
The local geometry, electronic structure, and vibrational features of three vicinal double interstitial defects in diamond, ICIC, ICIN, and ININ, are investigated and compared with those of three "simple" ⟨100⟩ interstitial defects, ICC, ICN, and INN, previously reported by Salustro et al. [Phys. Chem. Chem. Phys. 20, 16615 (2018)], using a similar quantum mechanical approach based on the B3LYP functional constructed from Gaussian-type basis sets, within a supercell scheme, as implemented in the CRYSTAL code. For the first time, the Fermi contact term and hyperfine coupling tensor B of the four open shell structures, ICIC, ICIN, ICC, and ICN, are evaluated and compared with the available experimental EPR data. For the two double interstitial defects, the agreement with experiment is good, whereas that for the single interstitials is found to be very poor, for which a likely reason is the incorrect attribution of the EPR spectra to uncertain atomic details of the micro-structure of the samples. The infrared spectra of the three double interstitial defects exhibit at least two peaks that can be used for their characterization.
Highlights
Natural and synthetic diamonds have attracted significant interest for many possible applications, such as high temperature diodes, transistors, thermistors, detectors, and windows for plasma heating in nuclear fusion power plants,2–4 in view of their high melting point, thermal conductivity, hardness, and wide bandgap
Phys. 20, 16615 (2018)], using a similar quantum mechanical approach based on the B3LYP functional constructed from Gaussian-type basis sets, within a supercell scheme, as implemented in the CRYSTAL code
We summarize the main results of this study, both for the purposes of comparison with the present results and to extend the analysis to the EPR constants, which were not investigated therein
Summary
Natural and synthetic diamonds have attracted significant interest for many possible applications, such as high temperature diodes, transistors, thermistors, detectors, and windows for plasma heating in nuclear fusion power plants, in view of their high melting point, thermal conductivity, hardness, and wide bandgap. The presence of intrinsic and extrinsic point defects in the crystalline lattice can dramatically modify some of the above properties so that over the last few decades, the investigation of both native and induced defects in diamond has been of continuing interest both from experimental and computational perspectives.. The vacancy V15–18 and ⟨100⟩ self-interstitial (see Fig. 1, top left, for the latter) are the most common, and their formation and recombination mechanisms have been investigated.. In the presence of nitrogen, three kinds of ⟨100⟩ interstitial defect (indicated here as Ixy, where x and y are the two threefold coordinated atoms) can, in principle, be found, namely, ICC, ICN , and INN. Two Ixy defects can interact to generate a more stable structure, in which two three-coordinated atoms and two four-coordinated atoms form approximately square, planar structures (see Fig. 2), referred to
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
