Miscibility gap in electrochemically oxygenated La{sub 2}CuO{sub 4+{delta}}
- Science and Technology Center for Superconductivity, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
- Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)
The miscibility gap of La{sub 2}CuO{sub 4+{delta}} was investigated by studying three electrochemically oxygenated samples with different oxygen contents, using variable-temperature neutron powder diffraction. The low-temperature lattice parameters of the two coexisting orthorhombic phases (antiferromagnetic, {ital Bmab} and superconducting, {ital Fmmm}) were found to be in good agreement with those determined for high-pressure annealed samples, indicating that the two techniques yield essentially identical samples, at least in this concentration range. A sample with {delta}{approx}0.032 remained phase separated up to 415 K and, above this temperature, was found to be single-phase tetragonal ({ital F}4/{ital mmm}). The phase separation temperature and the orthorhombic-to-tetragonal phase transition temperature were obtained for all samples, allowing the shape of the miscibility gap to be determined.
- Research Organization:
- Ames National Laboratory
- DOE Contract Number:
- W-7405-ENG-82; W-31109-ENG-38
- OSTI ID:
- 144770
- Journal Information:
- Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 9 Vol. 49; ISSN 0163-1829; ISSN PRBMDO
- Country of Publication:
- United States
- Language:
- English
Similar Records
Neutron and synchrotron x-ray powder-diffraction study of La sub 2 CuO sub 4+. delta
Synchrotron x-ray study of interstitial oxygen ordering in the superconducting phase of La{sub 2}CuO{sub 4+{delta}}