Trigonal ordering is evident from electron microscopy of quenched powders of composition YBa2Cu3O6.5. The powders are a mixture of phases, some of which are based upon two trigonal phases with a = 0.54 and c = 0.66 nm. In the first the yttrium and barium atoms order on the (111) planes of the parent perovskite structure rather than the (001) while in the second stacking sequence the yttrium layer of this structure is interchanged with one of the copper layers.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry