Absence of twinning in the 60 K superconducting phase of YBa2Cu3O7−δ

Autor: A. Nouruzi-Khorasani, K.N.R. Taylor
Rok vydání: 1989
Předmět:
Zdroj: Physica C: Superconductivity. 159:707-709
ISSN: 0921-4534
DOI: 10.1016/0921-4534(89)91307-5
Popis: The sequential observation of a number of areas of a large single crystal of YBa 2 Cu 3 O 7−δ using both optical and TEM microscopy has shown that in those regions in which there are no observable optical domains, there is also very little evidence for oxygen chain related twinning. In these same areas, electron diffraction (SAD) patterns clearly show the presence of the ( 1 2 0 0) super-lattice associated with an oxygen concentration close to O 6.5 (i.e. δ≈0.5). This has in turn been linked to the appearance of the 60 K transition and suggests that the lattice energetics of this alternate CuO chain occupancy does not favour twinning.
Databáze: OpenAIRE