Electromechanical dopant defect interaction in acceptor doped ceria

TL;DR

This study investigates how different acceptor dopants influence the electromechanical response of oxygen-deficient ceria, revealing that dopant-defect interactions significantly affect electrostrictive properties and time-dependent behaviors.

Contribution

It demonstrates the impact of dopant size and valence on defect interactions and electromechanical responses in ceria, highlighting the role of dopant-defect binding energy.

Findings

Weak dopant-vacancy binding (0.3 eV) leads to high electrostrictive coefficients and time-dependent effects.

Strong dopant-vacancy binding (0.6 eV) results in no time-dependent effects.

Different dopants tune the electromechanical behavior by modifying defect interactions.

Abstract

Oxygen defective cerium oxides exhibits a non classical giant electromechanical response that is superior to lead based electrostrictors. In this work, we report the key role of acceptor dopants, with different size and valence Mg2+, Sc3+, Gd3+, and La3+, on polycrystalline bulk ceria. Different dopants tune the electrostrictive properties by changing the electrosteric dopant defect interactions. We find two distinct electromechanical behaviors when the interaction is weak dopant vacancy binding energy 0.3 eV, electrostriction displays high coefficient, up to 10-17 m2V-2, with strongly time dependent effects. In contrast, we observe no time dependent effects when the interaction becomes strong 0.6 eV.