Composition of superconducting La/sub 2/CuO/sub 4+delta/: A superconductor doped by excess oxygen defects
Abstract
We have studied mixed-phase samples of bulk La/sub z/CuO/sub 4/ using neutron powder diffraction, thermogravimetric analysis and resistivity measurements. Samples fired at 950/degree/C and slowly cooled form in the K/sub 2/NiF/sub 4/ structure with CuO impurities for z<2 and La/sub 2/O/sub 3/ impurities for z>2. Neither La-vacancies nor stacking defects were found. The bulk resistivity of the samples show semiconducting behavior which is shorted at 38K by small amounts of superconducting material. The superconductivity is due to the presence of an oxygen-rich phase with stoichiometry La/sub 2/CuO/sub 4.08/. The occurrence of superconductivity in pure La/sub 2/CuO/sub 4.08/ with the same T/sub c/ as observed in the doped La/sub 1.85/Sr/sub 0.15/CuO/sub 4/ indicates that the excess oxygen provides the same level of doping as metal-ion substitution. 19 refs., 8 figs., 1 tab.
- Authors:
- Publication Date:
- Research Org.:
- Argonne National Lab., IL (USA)
- OSTI Identifier:
- 6193884
- Report Number(s):
- CONF-890426-11
ON: DE89013299
- DOE Contract Number:
- W-31109-ENG-38
- Resource Type:
- Conference
- Resource Relation:
- Conference: Spring meeting of the Materials Research Society, San Diego, CA, USA, 24 Apr 1989; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; COPPER OXIDES; SUPERCONDUCTIVITY; LANTHANUM OXIDES; STRONTIUM COMPOUNDS; SUPERCONDUCTORS; STOICHIOMETRY; BOND LENGTHS; DOPED MATERIALS; NEUTRON DIFFRACTION; OXYGEN; POINT DEFECTS; PRESSURE EFFECTS; ALKALINE EARTH METAL COMPOUNDS; CHALCOGENIDES; COHERENT SCATTERING; COPPER COMPOUNDS; CRYSTAL DEFECTS; CRYSTAL STRUCTURE; DIFFRACTION; DIMENSIONS; ELECTRIC CONDUCTIVITY; ELECTRICAL PROPERTIES; ELEMENTS; LANTHANUM COMPOUNDS; LENGTH; MATERIALS; NONMETALS; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; RARE EARTH COMPOUNDS; SCATTERING; TRANSITION ELEMENT COMPOUNDS; 360202* - Ceramics, Cermets, & Refractories- Structure & Phase Studies; 360204 - Ceramics, Cermets, & Refractories- Physical Properties
Citation Formats
Dabrowski, B, Hinks, D G, Jorgensen, J D, and Richards, D R. Composition of superconducting La/sub 2/CuO/sub 4+delta/: A superconductor doped by excess oxygen defects. United States: N. p., 1989.
Web.
Dabrowski, B, Hinks, D G, Jorgensen, J D, & Richards, D R. Composition of superconducting La/sub 2/CuO/sub 4+delta/: A superconductor doped by excess oxygen defects. United States.
Dabrowski, B, Hinks, D G, Jorgensen, J D, and Richards, D R. 1989.
"Composition of superconducting La/sub 2/CuO/sub 4+delta/: A superconductor doped by excess oxygen defects". United States.
@article{osti_6193884,
title = {Composition of superconducting La/sub 2/CuO/sub 4+delta/: A superconductor doped by excess oxygen defects},
author = {Dabrowski, B and Hinks, D G and Jorgensen, J D and Richards, D R},
abstractNote = {We have studied mixed-phase samples of bulk La/sub z/CuO/sub 4/ using neutron powder diffraction, thermogravimetric analysis and resistivity measurements. Samples fired at 950/degree/C and slowly cooled form in the K/sub 2/NiF/sub 4/ structure with CuO impurities for z<2 and La/sub 2/O/sub 3/ impurities for z>2. Neither La-vacancies nor stacking defects were found. The bulk resistivity of the samples show semiconducting behavior which is shorted at 38K by small amounts of superconducting material. The superconductivity is due to the presence of an oxygen-rich phase with stoichiometry La/sub 2/CuO/sub 4.08/. The occurrence of superconductivity in pure La/sub 2/CuO/sub 4.08/ with the same T/sub c/ as observed in the doped La/sub 1.85/Sr/sub 0.15/CuO/sub 4/ indicates that the excess oxygen provides the same level of doping as metal-ion substitution. 19 refs., 8 figs., 1 tab.},
doi = {},
url = {https://www.osti.gov/biblio/6193884},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 1989},
month = {Sun Jan 01 00:00:00 EST 1989}
}