Surface Effects in Ferroelectrics: Periodic Slab Computations for BaTiO_3
Abstract
Total energies, electronic structure, surface energies, polarization, potentials and charge densities were studied for slabs of BaTiO_3 using the Linearized Augmented Plane Wave (LAPW) method. The depolarization field inhibits ferroelectricity in the slabs, and the macroscopic field set up across a ferroelectric slab is sufficient to cause electronic states to span the gap and give a metallic band structure, but the band shifts are not rigid and O p states tend to pile up at the Fermi level. There are electronic surface states, especially evident on TiO_2 surfaces. The dangling bonds bond back to the surface Ti's and make the surface stable and reactive. The BaO surfaces are more ionic than the bulk.
Cite
@article{arxiv.mtrl-th/9609002,
title = {Surface Effects in Ferroelectrics: Periodic Slab Computations for BaTiO_3},
author = {Ronald E. Cohen},
journal= {arXiv preprint arXiv:mtrl-th/9609002},
year = {2008}
}
Comments
19 pages, revtex, 11 figures, proceedings of the Fourth Williamsburg Workshop on First-Principles Calculations for Ferroelectrics, to appear in Ferroelectrics