Microwave Dielectric Properties of Ba₂Ti₉O₂₀ Materials Prepared by Reaction Sintering Process

Ba₂Ti₉O₂₀ materials were prepared by reacting nano-sized BaTiO₃ powders (50 nm) with TiO₂ powders (∼100 nm). The materials prepared by calcination and sintering 2-step processes possess high sintered density (> 96.5% T.D.) and exhibit marvelous microwave dielectric properties (K = 39.5, Q × F = 33,000), which are markedly superior to the materials prepared via the reaction of BaCO₃ and TiO₂ powders. Direct reactive-sintering of nano-BaTiO₃ and TiO₂ mixture directly leads to even better microwave dielectric properties, which is ascribed to the more completeness in converting the BaTiO₃ particulates into Ba₂Ti₉O₂₀ Hollandite-like phase.

Keywords:

• Ba₂Ti₉O₂₀ reaction sintering process
• nano-BaTiO₃
• microwave dielectric property

Acknowledgments

Paper originally presented at AMF-4, Bangalore, India, December 12–15, 2003; received in final form April 10, 2005. The original Proceedings of the Fourth Asian Meeting on Ferroelectricity (AMF-4) are published in seven earlier volumes of FERROELECTRICS (Volumes 323–329, inclusive).