Orthorhombic-to-Tetragonal Transition in Re(1+x)Ba(2-x)Cu3O(7+ delta) (Re=Nd, Sm, and Eu)
Abstract
The orthorhombic-to-tetragonal structural phase transition in the high-Tc superconducting oxides of the type R1+xBa2-xCu3O7 delta (R (for rare earth) = Nd, Sm, and Eu) has been investigated using powder x-ray diffraction, dc resistivity, and thermogravimetric techniques. It was found that the orthorhombic-to-tetragonal transition occurs for samples whose nominal stoichiometric content of oxygen is greater than 7.0 (0 delta 0.3) as compared to less than 7.0 in YBa2Cu3O7 delta. With increasing (R/Ba) ratio in R1+xBa2- xCu30 delta, a clear convergence of multiple orthorhombic peaks to a well- defined single tetragonal peak was observed in the x ray diffraction pattern. The presence or orthorhombic distortion in this system appears to be essential for achieving 90-K superconductivity. Keywords: Barium, Copper oxides.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 15, 1988
- Accession Number
- ADA197174
Entities
People
- E. A. Hayri
- K. V. Ramanujachary
- Martha Greenblatt
- Shengxi Li
Organizations
- Rutgers University Department of Chemistry and Chemical Biology