Advanced ceramics are being developed for use in large area, high voltage devices in order to achieve high specific energy densities (greater than 10^6/ J/m^3/) and physical size reduction. Initial materials based on slip cast TiO2 exhibited a high bulk breakdown strength (BDS greater than 300 kV/cm) and high permittivity with low dispersion (epsilon approximately equal to 100). However, strong area and thickness dependencies were noted. To increase the BDS, multilayer dielectric compositions are being developed based on glass/TiO2 composites. The addition of glass increases the density (approximately equal to 99.8% theoretical), forms a continuous grain boundary phase, and also allows the use of high temperature processes to change the physical shape of the dielectric. The permittivity can also be manipulated since the volume fraction and connectivity of the glassy phase can be readily shifted. Results from this study on bulk breakdown of TiO2 multilayer structures with an area of 2 cm^2/ and 0.1 cm thickness have measured 650 kV/cm. Furthermore, a strong dependence of breakdown strength and permittivity has been observed and correlated with microstructure and the glass composition. This paper presents the interactive effects of manipulation of these variables.
W. Huebner et al., "High Breakdown Strength, Multilayer Ceramics for Compact Pulsed Power Applications," Proceedings of the 12th IEEE International Pulsed Power Conference, 1999, Institute of Electrical and Electronics Engineers (IEEE), Jan 1999.
The definitive version is available at http://dx.doi.org/10.1109/PPC.1999.823749
12th IEEE International Pulsed Power Conference, 1999
Materials Science and Engineering
Keywords and Phrases
TiO2; Casting; Ceramics; Compact Pulsed Power Applications; Continuous Grain Boundary Phase; Crystal Microstructure; Electric Breakdown; Electric Strength; Glass Composition; Glass/TiO2 Composites; Glassy Phase Connectivity; Grain Boundaries; High Breakdown Strength; High Permittivity; High Specific Energy Densities; High Temperature Processes; Low Dispersion; Microstructure; Multilayer Ceramics; Multilayer Dielectric Compositions; Permittivity; Pulsed Power Technology; Slip Cast TiO/Sub 2/; Volume Fraction
Article - Conference proceedings
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