Some oxygen defective metal oxides, such as cerium and bismuth oxides, have recently shown exceptional electrostrictive properties that are even superior to the best performing lead-based electrostrictors, e.g. lead-magnesium-niobates (PMN). Compared to piezoelectric ceramics, electromechanical mechanisms of such materials do not depend on crystalline symmetry, but on the concentration of oxygen vacancy (V O •• ) in the lattice. In this work, we investigate for the first time the role of oxygen defect configuration on the electro-chemomechanical properties. This is achieved by tuning the oxygen defects blocking barrier density in polycrystalline gadolinium doped ceria with known oxygen vacancy concentration, Ce0.9Gd0.1O2-δ, δ = 0.05. Nanometric starting powders of ca. 12 nm are sintered in different conditions, including field assisted spark plasma sintering (SPS), fast firing and conventional method at high temperatures. These approaches allow controlling grain size and Gd-dopant diffusion, i.e. via thermally driven solute drag mechanism. By correlating the electro-chemomechanical properties, we show that oxygen vacancy distribution in the materials play a key role in ceria electrostriction, overcoming the expected contributions from grain size and dopant concentration.

Enhanced Gd-doped ceria electrostriction: This study uncovers new anisotropic properties in thin films, enhancing the effect along with the 〈100〉 directions by one order of magnitude and proposing a new microscopic model to explain such findings.

Gadolium doped ceria, Gd:CeO2 (CGO), have recently been shown to possess an exceptional high electrostriction coefficient (Q), which is at the least three orders of magnitude larger than the best performing lead-based electrostrictors, e.g. Pb(Mn1/3Nb2/3)O3. Herein, we show that CGO thin films fabricated by a pulsed laser deposition method can be directly integrated onto the Si substrate by using TiN films of few nanometers as functional electrodes. The exceptional good coupling between TiN and Ce0.8Gd0.2O1.9 yields a high electrostriction coefficient of Qe = 40 m4 C−2 and a superior electrochemomechanical stability with respect to the metal electrodes.

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Electrostriction is a property of all the dielectric materials where an applied electric field induces a mechanical deformation proportional to the square of the electric field. The magnitude of the effect is usually minuscule. However, recent discoveries of symmetry-breaking phenomena at interfaces opens up the possibility to extend the electrostrictive response to a broader family of dielectric materials. 1,2 Here, we engineer the electrostrictive effect by epitaxially depositing alternating layers of

Cerium oxide is one of the most promising mixed ionic and electronic conducting material. Previous atomistic analysis has widely covered the effects of substitutional on oxygen vacancy migration. However, an...

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Oxygen-defective ceria, e.g. Gd-doped ceria, shows giant electromechanical properties related to a complex local rearrangement of its lattice.