From: David Vanderbilt <dhv@physics.rutgers.edu> Date: Thu, 19 Feb 1998 16:32:27 GMT (55kb)
Authors:
J. Padilla,
David Vanderbilt (Department of Physics and Astronomy, Rutgers University)
Comments: 11 pages with 2 postscript figures embedded. Uses Elsevier (elsart)
macros (provided) as well as epsf macros. Also available at
this http URL
Subj-class: Materials Science
We present first-principles total-energy calculations of (001) surfaces of SrTiO3. Both SrO-terminated and TiO2-terminated surfaces are considered, and the results are compared with previous calculations for BaTiO3 surfaces. The major differences are in the details of the relaxed surface structures. Our calculations argue against the existence of a large ferroelectric relaxation in the surface layer, as had been previously proposed. We do find some indications of a weak surface ferroelectric instability, but so weak as to be easily destroyed by thermal fluctuations except perhaps at quite low temperatures. We also compute surface relaxation energies and surface electronic band structures, obtaining results that are generally similar to those for BaTiO3.