Enhanced Electromechanical Response in Sm and Nd Co-doped Ceria

Highly oxygen defective cerium oxide, e.g., Gd-doped ceria, is a sustainable non-classical electrostrictor with electromechanical properties that are superior to lead-based piezoelectric metal oxides. Here, we report electrostriction in co-doped ceria (Sm, Nd) with a nominally low short-range vacancy-dopant association energy. Such a strategy results in a higher electrostrictive strain coefficient (M₃₃), up to 10⁻¹⁷ (m/V)² at lower-frequencies, and unexpected electromechanical strain saturation and relaxation effects. These outcomes support the hypothesis that electrostriction is strongly influenced by the local environment of oxygen vacancy and by the ionic migration blocking factors built-in the microstructure.