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Published on: February 8, 2018
Superconductivity in Alkaline Earth-Substituted La2CuO4-y.
Science (New York, N.Y.)
|April 3, 1987
Summary
Alkaline earth doping in La(2)CuO4-y ceramics enhances superconductivity. Strontium doping shows higher onset temperatures and diamagnetism, indicating electronic changes are key, not just ionic size.
Area of Science:
- Materials Science
- Solid-State Physics
- Superconductivity
Background:
- Lanthanum cuprate (La(2)CuO4-y) is a parent compound for high-temperature superconductors.
- Doping with alkaline earth ions like Ca(2+), Sr(2+), and Ba(2+) is known to induce superconductivity.
Purpose of the Study:
- To investigate the effect of Ca(2+), Sr(2+), and Ba(2+) doping on the superconductive properties of La(2)CuO4-y.
- To determine whether electronic changes or ionic size effects are primarily responsible for superconductivity.
Main Methods:
- Preparation of La(2)CuO4-y ceramics doped with small percentages of Ca(2+), Sr(2+), and Ba(2+).
- Measurement of electrical resistivity and magnetic susceptibility to identify superconductive onsets and diamagnetism.
Main Results:
- All doped La(2)CuO4-y samples exhibited superconductive onsets.
- La(2)CuO4-y doped with Sr(2+) showed a higher onset temperature and greater superconductivity-induced diamagnetism compared to Ba(2+) and Ca(2+) doping.
- The ionic radius of Sr(2+) is similar to that of La(3+), suggesting substitution at the La site.
Conclusions:
- The electronic changes induced by alkaline earth doping are the primary drivers of superconductivity in La(2)CuO4-y.
- Strontium doping is particularly effective in enhancing superconductive properties, likely due to favorable electronic interactions and substitution patterns.
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