Periodic Slab LAPW Computations for Ferroelectric BaTiO3
نویسنده
چکیده
Linearized augmented plane wave (LAPW) calculations are performed for periodic (001) and (111) slabs of BaTiO3 to understand the effects of surfaces on ferroelectric BaTiO3. The (111) slab is found to be much less stable than the (001) slab. The average surface energies are respectively 3700 erg/cm and 1600 erg/cm. The depolarization field is sufficiently large in the ideal unrelaxated slab to completely inhibit the ferroelectric instability. No midgap surface states are evident, but there are surface states in the upper gap in the unrelaxed slab and at the top of the valence band. The dangling surface Ti bonds self-heal making the Ti-O surface very reactive and an excellent epitaxial substrate. The charge density on atoms only one unit cell away from the surface are almost identical to the bulk.
منابع مشابه
Surface Effects in Ferroelectrics: Periodic Slab Computations for BaTiO3
Total energies, electronic structure, surface energies, polarization, potentials and charge densities were studied for slabs of BaTiO3 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 ba...
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