Diffuse scattering of fast electrons in barium titanate

Abstract

Dynamical electron diffraction theory is used to explain structure in diffuse-scattering patterns from barium titanate. A point-scattering model as well as an Einstein model for TDS is used to account explicitly for the effects of scattering from each atomic site within the unit cell. The angular dependence of TDS indicates a significant contribution from O sites. Effects of static atomic displacements corresponding to the paraelectric/ferroelectric phase transition at ca 413 K are investigated on a point-scattering model. Ability to concentrate current density on specific crystallographic sites may provide a powerful tool for the investigation of thermal scattering mechanisms.