Effective Dielectric Function in High-Permittivity Ceramics and Films

Abstract

Effective dielectric function in granular materials (ceramics and polycrystalline films) is discussed in terms of the recently developed generalized brick-wall model for arbitrary particle shape and size. The model is applied to the discussion of the dead grain-boundary layers in SrTiO ₃ which are supposed to be formed by frozen dipoles at polar grain boundaries with the polarization penetrating inside the grain.

Keywords:

• Effective dielectric response
• composites
• dead layers
• strontium titanate

PACS:

• 68.35
• 73.61.Ng
• 77.22.Ch
• 78.30.−j

Acknowledgments

The authors thank J. Hlinka and T. Ostapchuk for helpful discussions. The work was supported by the Grant Agency of the Czech Republic (projects 202/03/0551 and 202/04/0993), Academy of Science of the Czech Rep. (project AVOZ 10100520) and Ministry of Education of the Czech Rep. (project COST OC 525.20/00).