Influence of Y₂O₃ Doping on Phase Evolution and Dielectric Characteristics of ZrO₂ Ceramics

Abstract

Improvements in phase stability and dielectric characteristics can broaden the applications of zirconia in ceramics. Herein, a series of Y2O3-stabilized zirconia (YSZ) ceramics are synthesized using solid-state sintering, followed by an investigation into their phase evolution, grain size, dielectric constant, and breaking field. As the Y2O3 content increases from 0 wt% to 4 wt%, the as-grown YSZ ceramics undergo a distinct phase transformation, transitioning from monoclinic to monoclinic + tetragonal and further to monoclinic + tetragonal + cubic, before finally returning to monoclinic + cubic. Significant changes occur in the internal microstructure and grain size of the ceramics as the phase composition alters, resulting in a reduction in grain size from 3.17 μm to 0.27 μm. Moreover, their dielectric constants exhibit an increasing trend as the Y2O3 content increases, rising from 3.92 to 13.2. Importantly, the dielectric breakdown field of these YSZ ceramics shows a similar variation to the phase evolution, ranging from 0.11 to 0.15 MV/cm. This study sheds light on the phase evolution and dielectric properties of YSZ ceramics, offering an efficient strategy for enhancing their dielectric performances.

Keywords

• Y₂O₃-doped zirconia ceramics
• phase transformation
• grain size
• dielectric constant
• breaking field