Non-classical electromechanical behavior in multi-cation stabilized zirconia (Yb0.04Y0.04Gd0.04Nb0.10-Zr0.78O2-δ) ceramics

This work aims to investigate the electromechanical properties of a new mixed tetragonal-cubic composition: multi-cation stabilized tetragonal zirconia polycrystal (MC-TZP) ceramics, stabilized by 2 mol% Yb 2 O 3 –2 mol% Y 2 O 3 –2 mol% Gd 2 O 3 –5 mol% Nb 2 O 5 . The evolution of microstructure, dielectric, mechanical, and ferroelastic properties was also characterized. The MC-TZP powder was synthesized by solid-state reaction and then consolidated by two sintering methods, i.e., hot pressing and conventional sintering. Hot pressing produced an ultrafine microstructure with small grains, while conventional sintering resulted in larger grains. Both ceramics samples exhibit large longitudinal electrostrictive (M 33 ≥ 1 * 10 -17 m 2 /V 2 ) coefficients at 1 Hz and a typical frequency-related relaxation effect, with the hot-pressed material demonstrating a relatively higher M 33 value. This enhancement correlates with improved electrical properties, characterized by a higher dielectric constant and electrical conductivity compared to the conventionally sintered counterpart.