Characteristic of Ba₂Ti₉O₂₀ Microwave Dielectric Materials Prepared by Modified Co-Precipitation Method

Modified co-precipitation process (MCP), which combines the automatic pH-value control and supersonic spraying of co-precipitants, was used to synthesize nano-sized Ba₂Ti₉O₂₀ precursors (48.8 nm). Kinetics for crystallization process is markedly enhanced when the O₂ atmosphere was used to replace for air atmosphere in the calcinations and sintering processes. When O₂-processed, high density Ba₂Ti₉O₂₀ materials (> 94%T.D.), possessing good microwave properties (K = 38.7 and Q × F = 30,502), can be obtained by sintering the sample at 1200°C, 4 h, which is markedly lower than the sintering temperature need when processed in air (1250°C 4 h).

Keywords:

• Ba₂Ti₉O₂₀
• modified co-precipitation process
• nano-sized powder
• 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).