Changes in structure and electrical conductivity of rare-earth titanate pyrochlores under highly reducing atmosphere
| Autor: | Aurélie Rolle, Nicoleta Cioatera, E. Panaintescu, Rose-Noëlle Vannier, C.I. Spinu, Simona Somacescu, Elena-Adriana Voinea |
|---|---|
| Přispěvatelé: | Department of Chemistry, University of Craiova, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, Institute of Physical Chemistry « Ilie Murgu lescu », Romanian Academy, Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Materials science
Hydrogen Pyrochlore Analytical chemistry chemistry.chemical_element Mineralogy 02 engineering and technology Conductivity engineering.material 010402 general chemistry 7. Clean energy 01 natural sciences Electrical resistivity and conductivity Materials Chemistry [CHIM]Chemical Sciences ComputingMilieux_MISCELLANEOUS Process Chemistry and Technology Reducing atmosphere [CHIM.MATE]Chemical Sciences/Material chemistry 021001 nanoscience & nanotechnology Decomposition Titanate 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Dielectric spectroscopy chemistry Ceramics and Composites engineering 0210 nano-technology |
| Zdroj: | Ceramics International Ceramics International, Elsevier, 2016, 42 (1), pp.1492-1500. ⟨10.1016/j.ceramint.2015.09.095⟩ Ceramics International, 2016, 42 (1), pp.1492-1500. ⟨10.1016/j.ceramint.2015.09.095⟩ |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2015.09.095⟩ |
| Popis: | M2Ti2O7 (M=Y, Gd, Sm) pyrochlore materials are synthesized by a Pechini method. The pyrochlore phase evolution with temperature under air and under highly reducing conditions (2% H2 in Ar) is investigated using high-temperature X-ray diffraction. The decomposition of pyrochlore oxides into their component single oxides is evidenced when they are exposed to a hydrogen atmosphere. Sm2Ti2O7 pyrochlore is the most stable compound, while Gd2Ti2O7 undergoes a strong reduction even at RT. The bulk electrical conductivity of the samples is evaluated by electrochemical impedance spectroscopy. The greatest increase in conductivity is evidenced for Gd2Ti2O7, while Sm2Ti2O7 is the most stable among the investigated compounds. Besides oxygen ions and electrons, the contribution of hydrogen defects to the bulk conductivity must be considered in such reducing atmosphere. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect