The permittivity of two primary phases within the Bi2O3-ZnO-Ta2O5 system was measured from 100 Hz to approximately 8.7 GHz. A cubic pyrochlore (Bi3/2Zn1/2)(Zn1/2Ta3/2) O7 phase (α phase) exhibited a dielectric constant of 71 at low frequency which decreased to 64 approximately 10 GHz. A lower symmetry zirconolite Bi2(Zn1/3Ta2/3)2 O7 phase (β phase) was also measured and had a frequency independent dielectric constant of 60. The temperature dependence of the capacitance (τC), measured from -55 to 120°C, was 78 ppm/°C for the β phase and nonlinear for the α phase having no unique slope. The primary difference in dielectric properties between these two phases was a low-temperature relaxation of the α phase, which is modeled as a basic Debye-type relaxation.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering