Synthesis, characterization, phase diagrams and superconducting and normal state magnetic properties of La{sub 2-x}Sr{sub x}CuO{sub 4} (0 {le} x {le} 0.08) and electrochemically oxidized La{sub 2-x}Sr{sub x}CuO{sub 4+{delta}} (0 {le} x {le} 0.33, 0 {le} {delta} {le} 0.12)
Abstract
La{sub 2-x}Sr{sub x}CuO{sub 4}(0{le}x{le}0.15) can all be intercalated with oxygen by a novel electrochemical oxidation method. Bulk superconductivity is found with an onset {Tc} {approx} 40 K for the whole range 0.01 {le} x {le} 0.15; for x = 0.25 and 0.33, the electrochemical oxidation did not improve the superconducting properties. The magnetic susceptibility x(T = 50-320 K) data for La{sub 2}CuO{sub 4.11} and La{sub 1.92}Sr{sub 0.08}CuO{sub 4.07} are nearly identical with those of conventionally prepared La{sub 1.85}Sr{sub 0.15}CuO{sub 4}, indicating that the hole doping level (p) in the CuO{sub 2} planes of the three compounds is nearly the same. Combined thermogravimetric analysis and iodometric titration experiments indicate that part of the intercalated oxygen has a formal valence close to -1. The maximum doped-hole concentration in the CuO{sub 2} planes that can be achieved from combined Sr-doping and electrochemical oxygen doping for 0 {le} x {le} 0.15 is p {approx} 0.16 holes/formula unit. Oxygen can also intercalate into single crystal La{sub 2}CuO{sub 4} through a slow electrochemical oxidation process. The required low current and long time for the charging process reflects that the oxygen intercalation for a single crystal is limited by its small specific surface area and long diffusionmore »
- Authors:
- Publication Date:
- Research Org.:
- Iowa State Univ. of Science and Technology, Ames, IA (United States)
- OSTI Identifier:
- 111258
- Resource Type:
- Miscellaneous
- Resource Relation:
- Other Information: TH: Thesis (Ph.D.); PBD: 1993
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 66 PHYSICS; 36 MATERIALS SCIENCE; HIGH-TC SUPERCONDUCTORS; MAGNETIC PROPERTIES; SYNTHESIS; COPPER OXIDES; LANTHANUM COMPOUNDS; STRONTIUM COMPOUNDS; PHASE DIAGRAMS; MAGNETIC SUSCEPTIBILITY; ELECTROCHEMISTRY
Citation Formats
Chou, F. Synthesis, characterization, phase diagrams and superconducting and normal state magnetic properties of La{sub 2-x}Sr{sub x}CuO{sub 4} (0 {le} x {le} 0.08) and electrochemically oxidized La{sub 2-x}Sr{sub x}CuO{sub 4+{delta}} (0 {le} x {le} 0.33, 0 {le} {delta} {le} 0.12). United States: N. p., 1993.
Web.
Chou, F. Synthesis, characterization, phase diagrams and superconducting and normal state magnetic properties of La{sub 2-x}Sr{sub x}CuO{sub 4} (0 {le} x {le} 0.08) and electrochemically oxidized La{sub 2-x}Sr{sub x}CuO{sub 4+{delta}} (0 {le} x {le} 0.33, 0 {le} {delta} {le} 0.12). United States.
Chou, F. 1993.
"Synthesis, characterization, phase diagrams and superconducting and normal state magnetic properties of La{sub 2-x}Sr{sub x}CuO{sub 4} (0 {le} x {le} 0.08) and electrochemically oxidized La{sub 2-x}Sr{sub x}CuO{sub 4+{delta}} (0 {le} x {le} 0.33, 0 {le} {delta} {le} 0.12)". United States.
@article{osti_111258,
title = {Synthesis, characterization, phase diagrams and superconducting and normal state magnetic properties of La{sub 2-x}Sr{sub x}CuO{sub 4} (0 {le} x {le} 0.08) and electrochemically oxidized La{sub 2-x}Sr{sub x}CuO{sub 4+{delta}} (0 {le} x {le} 0.33, 0 {le} {delta} {le} 0.12)},
author = {Chou, F},
abstractNote = {La{sub 2-x}Sr{sub x}CuO{sub 4}(0{le}x{le}0.15) can all be intercalated with oxygen by a novel electrochemical oxidation method. Bulk superconductivity is found with an onset {Tc} {approx} 40 K for the whole range 0.01 {le} x {le} 0.15; for x = 0.25 and 0.33, the electrochemical oxidation did not improve the superconducting properties. The magnetic susceptibility x(T = 50-320 K) data for La{sub 2}CuO{sub 4.11} and La{sub 1.92}Sr{sub 0.08}CuO{sub 4.07} are nearly identical with those of conventionally prepared La{sub 1.85}Sr{sub 0.15}CuO{sub 4}, indicating that the hole doping level (p) in the CuO{sub 2} planes of the three compounds is nearly the same. Combined thermogravimetric analysis and iodometric titration experiments indicate that part of the intercalated oxygen has a formal valence close to -1. The maximum doped-hole concentration in the CuO{sub 2} planes that can be achieved from combined Sr-doping and electrochemical oxygen doping for 0 {le} x {le} 0.15 is p {approx} 0.16 holes/formula unit. Oxygen can also intercalate into single crystal La{sub 2}CuO{sub 4} through a slow electrochemical oxidation process. The required low current and long time for the charging process reflects that the oxygen intercalation for a single crystal is limited by its small specific surface area and long diffusion distance. The anisotropic superconducting, magnetic and transport properties are summarized and compared with those of polycrystalline La{sub 2}CuO{sub 4+{delta}} as well as of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} and La{sub 2-x}Sr{sub x}CuO{sub 4} single crystals. The single crystal La{sub 2}CuO{sub 4+{delta}} has a maximum {Tc} {approx} 40 K, which is lower than that ({Tc} {approx} 42-45) of the corresponding polycrystalline samples.},
doi = {},
url = {https://www.osti.gov/biblio/111258},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Dec 31 00:00:00 EST 1993},
month = {Fri Dec 31 00:00:00 EST 1993}
}