MIRANDA, Laura, BOULAHYA, Khalid, VARELA, Aurea, GONZÁLEZ-CALBET, José M., PARRAS, Marina, HERNANDO, María, FERNÁNDEZ-DÍAZ, M. Teresa, FETEIRA, Antonio and SINCLAIR, Derek C. (2007). Structure−property relationships of the 10H Hexagonal-Type Perovskite BaMn0.4Fe0.6O2.73. Chemistry of Materials, 19 (14), 3425-3432.Full text not available from this repository.
The crystal structure of BaMn0.4Fe0.6O2.73, a recently identified oxygen-deficient 10H-type hexagonal perovskite in the system BaMn1-xFexO3-y, has been established by a combination of electron microdiffraction and neutron diffraction. The structure (space group P63/mmc, a = 5.74435(5) Å, and c = 24.0331(3) Å) can be described by a stacking sequence (hch‘ch)2 along the c-axis with the anion deficiency located exclusively in the h‘-BaO3-type layers. The anion distribution in the h‘-BaO3 layers differs significantly from that observed for 10H BaFeO2.8 and results in a 70:30 random distribution of corner-sharing tetrahedral Fe2O7 dimers and face-sharing octahedral (Mn,Fe)2O9 dimers as opposed to the exclusive Fe2O7 dimers in 10H BaFeO2.8. The difference is attributed to the preference of Mn for octahedral coordination. The compound is a “leaky” insulator at room temperature with a permittivity of 20. The conduction mechanism has low activation energy, 0.3 eV, and is consistent with polaronic hopping associated with the Fe and/or Mn ions.
|Research Institute, Centre or Group:||Materials and Engineering Research Institute > Structural Materials and Integrity Research Centre > Centre for Corrosion Technology|
|Depositing User:||Hilary Ridgway|
|Date Deposited:||06 Jun 2012 15:07|
|Last Modified:||06 Jun 2012 15:07|
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