Abstract
The Ruddlesden-Popper ferrite Sr3Fe2O6+δ and its titania-doped derivatives Sr3Fe2-xTixO6+δ, where 0<x≤2, have been characterized by X-ray powder diffraction and thermogravimetry. The changes in oxygen content and crystal lattice parameters are consistent with titanium ions entering the solid solution in 4+ oxidation state with octahedral oxygen coordination. Electronic conductivity measurements on polycrystalline Sr3Fe2O6+δ and Sr3Fe0.8Ti1.2 O6+δ in the temperature range 750-1000°C and oxygen partial pressures (pO2) varying between 10-20 and 0.5 atm revealed that the predominant partial conductivity of electrons is proportional to pO2-1/4 in the low pO2 region, while the predominant partial contribution of holes to the conductivity is proportional to pO2+1/4 in the high pO2 range. The pressure-independent oxygen ion conductivity is found to decrease with the increase in titanium content. A possible pathway for oxygen ion migration is discussed in relation to disorder in the oxygen sublattice and titanium doping.
Original language | English |
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Pages (from-to) | 275-283 |
Number of pages | 9 |
Journal | Journal of Solid State Chemistry |
Volume | 168 |
Issue number | 1 |
DOIs | |
Publication status | Published - Oct 2002 |
Keywords
- Electron conductivity
- Oxygen conductivity
- Oxygen transfer
- Ruddlesden-Popper ferrite
- Thermopower
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry