Missing-atom structure of diamond Sigma 5 (001) twist grain boundary
2011 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 84, no 14, 144112- p.Article in journal (Refereed) Published
We carried out a combined experimental and theoretical study of grain boundaries in polycrystalline diamond, aimed at achieving the conditions in which grain boundaries are equilibrated. Raman spectra of compacted at high-pressure and high-temperature diamond powders allow us to identify signals from sp(2)-bonded atoms, in addition to a strong peak at 1332 cm(-1), corresponding to sp(3)-bonded carbon. To verify our interpretation of the experiment, Sigma 5 (001) twist grain boundaries of polycrystalline diamond were studied by means of molecular dynamics simulations using the technique proposed by von Alfthan et al. [Phys. Rev. Lett. 96, 055505 (2006)]. We find that grain-boundary (GB) configurations, from which one atom is removed, have significantly lower energy compared to those obtained with conventional techniques. These calculated GBs are highly ordered, a few monolayers thick, in agreement with experimental observations, and are primarily sp(2) bonded. This paper underlines the importance of varying the number of atoms within GBs in molecular dynamics simulations to correctly predict the GB ground-state structure.
Place, publisher, year, edition, pages
American Physical Society , 2011. Vol. 84, no 14, 144112- p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-72025DOI: 10.1103/PhysRevB.84.144112ISI: 000296287600002OAI: oai:DiVA.org:liu-72025DiVA: diva2:456009
Funding Agencies|Swedish Foundation for Strategic Research via strategic center MS2
E||Goran Gustafsson Foundation for Research in Natural Sciences and Medicine||Swedish Research Council (VR)||DFG|SPP1236|2011-11-112011-11-112012-06-21