ACu 3Ti 4O 12 and ACu 3Ru 4O 12 perovskites: high dielectric constants and valence degeneracy
Abstract
ACu 3M 4O 12 phases crystallize in perovskite-related structure (space group: Im3). Dielectric constants for ACu 3Ti 4O 12 phases are found to be much higher than expected based on the dielectric polarizabilities of the constituent atoms, and this property seems not to be related to either underlying ferroelectric or relaxor behavior. New data on these compounds is presented. Valence degeneracy between Cu and Ru is shown to exist for ACu 3Ru 4O 12 phases where A may be a +1, +2, or +3 cation. Structural refinements based on single crystal X-ray diffraction data are given for CaCu 3Ti 4O 12, CaCu 3Ru 4O 12 and NaCu 3Ru 4O 12.
- Publication:
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Solid State Sciences
- Pub Date:
- March 2002
- DOI:
- 10.1016/S1293-2558(01)01262-6
- Bibcode:
- 2002SSSci...4..347S