| Abstract: | The effects of the electrode-bulk interface on the dielectric properties of Ba0.9988Bi0.0008Zr0.2Ti0.8O3 (BBZT) ceramics with a slight change in the thickness (≤15%) were investigated. In BBZT ceramics, the dielectric constant decreases with the increase of thickness, and the interface between electrode and bulk ceramics is considered the main reason. A formula is proposed to calculate the dielectric constant of bulk materials. According to the formula, the electrode-bulk interface has a slight influence on the frequency characteristics of the dielectric constant. However, the ferroelectric to paraelectric phase transition temperature changes from 10 °C to 15 °C for bulk ceramics when the electrode-bulk interface is taken into consideration. In a range of 0 °C–75 °C, obvious differences between εB and εT are observed due to the electric field induced by removable carriers. The dielectric tunability is degraded by the influence of electrode-bulk interface. BBZT ceramics have considerable tunability (>65% @100 kHz) and a low loss tangent (<0.006 @100 kHz) with an excellent FOM value (>270). This study demonstrates a method of calculating the dielectric constants of bulk ceramic layers and provides a theoretical basis for improving the performance of bulk materials using interfacial layers. |
