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Enhanced superconductivity by rare-earth metal doping in phenanthrene
1Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
Summary
We synthesized La- and Sm-doped phenanthrene, observing superconductivity near 6 K. These findings suggest unconventional superconductivity in doped phenanthrene, offering new insights into organic superconductors.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Organic Superconductivity
Background:
- Organic superconductors exhibit unique electronic properties.
- Doping is a key method to tune superconductivity in organic materials.
- Phenanthrene-based compounds are a class of organic superconductors.
Purpose of the Study:
- To synthesize and characterize lanthanum (La) and samarium (Sm)-doped phenanthrene.
- To investigate the superconducting properties, including critical temperature (T(c)) and shielding fraction.
- To explore the nature of superconductivity in these doped systems.
Main Methods:
- Synthesis of La- and Sm-doped phenanthrene powder samples.
- Measurement of superconductivity using temperature-dependent magnetic susceptibility.
- Analysis of Raman spectra to study charge transfer effects.
Main Results:
- Superconductivity observed at T(c) around 6 K for both La- and Sm-doped phenanthrene.
- T(c) values of 6.1 K (La) and 6.0 K (Sm) were recorded, showing enhancement over other phenanthrene superconductors.
- Superconductive shielding fractions reached 46.1% (La) and 49.8% (Sm) at 2 K.
- Raman spectra indicated a redshift of 7 cm⁻¹ per electron due to charge transfer from dopants.
Conclusions:
- The observed superconductivity in La- and Sm-doped phenanthrene suggests unconventional pairing mechanisms.
- The minimal impact of magnetic Sm doping on T(c) and positive pressure dependence support unconventional superconductivity.
- Charge transfer dynamics are consistent across different dopants in phenanthrene superconductors.
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