Stability of the Bulk Phase of Layered ZnO
Condensed Matter journal club
Stability of the Bulk Phase of Layered ZnO
- Event time: 11:30am
- Event date: 25th November 2011
- Speaker: Linggang Zhu (Formerly School of Physics & Astronomy, University of Edinburgh)
- Location: Room 2511, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB
Event details
Abstract
Recently a novel phase of ZnO has been synthesized which is analogous to a-boron nitride, although more three dimensional, and consists of planar hexagonal sheets of ZnO. Examining the dynamic stability of the structure, we find unstable phonon modes over a considerable part of the Brillouin zone. Local-density approximation (LDA) and generalized gradient approximation level calculations have usually been able to predict the structural stability of s-p bonded systems. The failure in the present case is a surprise and is traced to the self-interaction error which incorrectly locates the localized Zn d states in the valence band of ZnO. Correcting for this with a Hubbard-like U on the Zn d states, the optimized structure is predicted to be stable. This highlights the fact that the large bond length contraction that one finds in going from sp3- to sp2-type bonding results in an increased necessity to correct for self-interaction errors.pdf version of paper here
Authors
Bipul Rakshit and Priya Mahadevan
About Condensed Matter journal club
Given the diversity of research in the CM group, chosen topics vary widely. We tend to stick to high-impact journals - Nature, Science, PNAS and PRL have been popular - but this is not prescriptive..