Electromechanical dopant–defect interaction in acceptor-doped ceria

Abstract

Oxygen defective cerium oxides CeO2-δ 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...

Trivalent Dopant Size Influences Electrostrictive Strain in Ceria Solid Solutions

“…It is important to note that for a material like ceria, in which dislocation movement at room temperature is not likely, primary creep deformation is a clear sign of viscoelastic (of which anelasticity is one example) behavior. The electrostriction strain coefficient, measured in both thin films and ceramics at room temperature, is at least 2 orders of magnitude higher ,,− than expected from the empirical scaling law proposed by Newnham and co-workers. , …”

“…Although in the case of perovskite piezo-ceramics, grain size is thought to play a role in modulating the electromechanical strain response, for aliovalent-doped ceria, no obvious influence of grain size or size distribution (Figure ) has been observed. Published electrostriction coefficients of thin films and bulk samples are very similar, although grain sizes may differ by up to 3 orders of magnitude. ,,,,− …”

“…Both values are much larger than predicted from the scaling law obeyed by diverse, classical (Newnham , ) electrostrictors (≈10 –20 m 2 /V 2 ). Second, increasing the dopant concentration results in a marked decrease in the quasistatic electrostriction strain coefficient, while the high-frequency and low-frequency electrostriction strain coefficients are both ≈10 –18 m 2 /V 2 . ,, The microscopic features responsible for such strikingly large electrostrictive strain and room-temperature anelasticity are still a subject of considerable debate. Recent theoretical studies, − high-energy resolution X-ray absorption spectroscopy, and reverse Monte Carlo modeling constrained by extended X-ray absorption fine structure spectroscopy (EXAFS) and X-ray diffraction (XRD) data, with supercell (5 × 5 × 5 fluorite unit cells), have provided additional key important information and insights.…”

Low-temperature synthesis of bismuth titanate by modified citrate amorphous method

“…where ε is the real dielectric constant, tanδ is the loss factor, t is the sample thickness, ω is the angular frequency, A is the sample area, ε 0 is the dielectric constant of vacuum, ′′ is the imaginary impedance, and ′ is the real impedance [47,48].…”

Gigantic electro-chemo-mechanical properties of nanostructured praseodymium doped ceria

“…20 Trivalent and divalent dopants such as Gd 3+ , Sm 3+ , Ca 2+ , Sc 3+ are reported in the literature. 15,[29][30][31] Tetravalent cations, e.g. Zr 4+ and Pr 4+ , are common in ceria solutions for other applications.…”