The dielectric relaxation behavior of the fluorite structured nanocrystalline Ce0.8Gd0.1Pr0.1 O 2-δ compound was studied in the temperature range of 200-550 °C. Two different types of relaxation processes were observed corresponding to (1) defect pairs such as (Pr′Ce - VO) and (Gd′Ce - VO) and (2) the trimers such as (Pr′Ce - VO - Gd′Ce). The correlation between ionic conduction and the dielectric properties of the nanocrystalline material is discussed. Very low values of the migration energy and association energy of the oxygen vacancies are observed, which are 0.42 and 0.03 eV, respectively. The obtained value of association energy agrees well with the theoretical prediction on doubly doped ceria. © 2009 American Institute of Physics.

Sankaranarayanan V

Department Of Physics

Cerium

Dielectric properties

Dielectric relaxation

Gadolinium

Nanocrystalline materials

Oxygen

Oxygen vacancies

ASSOCIATION ENERGIES

Defect pairs

DIELECTRIC RELAXATION BEHAVIORS

DOPED CERIAS

Intermediate temperatures

MIGRATION ENERGIES

NANO-CRYSTALLINE

Nano-structured

Temperature ranges

THEORETICAL PREDICTIONS

CERIUM COMPOUNDS

Fulltext

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IIT Madras

Dielectric relaxation properties of nanostructured Ce0.8Gd0.1Pr0.1O2−δ material at intermediate temperatures

Applied Physics Letters

Electrical and dielectric properties, and their correlations were discussed in the nanostructured Ce0.8 Dy0.2 O2-δ materials with average grain sizes of 15, 35, and 58 nm using the dielectric functions such as dielectric permittivity (ε′), loss tangent (tan δ), and electric modulus (M″). The ionic transport mechanism varies with the grain size of the materials such that the material with an average grain size of 35 nm exhibited a higher value of ionic conductivity above 440°C (with σ=8.96× 10-4 S cm-1 at 550°C), whereas the material with an average grain size of 15 nm shows higher value conductivity at lower temperatures. The oxygen vacancy in the material decreases with the decrease in grain size. The migration energy of oxygen ions also decreases with the decrease in grain size of the nanostructured Ce0.8 Dy 0.2 O2-δ material. The material with an average grain size of 35 nm shows a very low value association energy (i.e., 0.05 eV) compared to the others. At temperatures below 420°C, the local motion of oxygen vacancies around Dy+3 controls the conductivity of all the materials, and at higher temperatures, the conductivity in the materials with a larger grain size is mainly due to the long-range motion of vacancies. © 2010 The Electrochemical Society.

Journal of the Electrochemical Society

Grain size effect on electrical and dielectric properties of the nanostructured Dy-doped ceria (Ce0.8 Dy0.2 O 2-δ)

Journal of Nanoparticle Research

Gadolinium doped Ceria nanocrystals synthesized from mesoporous silica

Journal of Materials Science

RETRACTED ARTICLE: Determination of dopant of ceria system by density functional theory

Solid State Ionics

Dielectric relaxations in the Ce1−xNdxO2−δ system

Relationship between oxide-ion conductivity and dielectric relaxation in Sm-doped CeO2

Journal of Alloys and Compounds

Study on La and Y co-doped ceria-based electrolyte materials

Dielectric relaxation properties of nanostructured Ce0.8Gd 0.1Pr0.1O2-δ material at intermediate temperatures

Journal	Applied Physics Letters
ISSN	00036951
Open Access	No