Dielectric properties of Ta₂O₅-BN polycrystalline ceramics

The dielectric properties of (Ta₂O₅)_{1 x}(BN)_x polycrystalline ceramics are reported for 0.0 < x < 0.25. Measurements were made at 1 MHz and temperatures between O and 100°C. The dielectric constant is moderately enhanced in the high temperature tantalum oxide phase at low BN concentrations; it then decreases to an essentially composition-independent value at higher concentrations where the low temperature form of tantalum oxide is stabilized. In the low temperature form, above x = 0.05, there is a significant decrease in the temperature coefficient of the dielectric constant with increas-ing BN content.