Electromechanical dopant defect interaction in acceptor doped ceria

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.