Ba2phenanthrene is the main component in the Ba-doped phenanthrene superconductor

Area of Science:

• Materials Science
• Solid State Physics
• Computational Chemistry

Background:

• Barium-doped phenanthrene is a material of interest for its superconducting properties.
• Understanding the precise crystal structure and phase composition is crucial for explaining its electronic behavior.

Purpose of the Study:

• To systematically investigate the crystal structure of Ba-doped phenanthrene at various doping levels.
• To reconcile discrepancies between experimental observations and theoretical models for Ba-doped phenanthrene.

Main Methods:

• First-principles calculations were employed to model the electronic and structural properties.
• Simulations of X-ray diffraction (XRD) spectra were used to validate structural models.
• Comparison of simulated XRD spectra, space group symmetry, and lattice parameters with experimental data.

Main Results:

• Simulated XRD spectra and structural parameters for Ba1.5phenanthrene did not match experimental data.
• Simulated results for Ba2phenanthrene showed good agreement with experimental measurements.
• Discrepancies in XRD peak strengths were attributed to the presence of undoped phenanthrene.

Conclusions:

• The superconducting sample likely consists of a mixture of Ba2phenanthrene and undoped phenanthrene, rather than a uniform Ba1.5phenanthrene phase.
• Ba2phenanthrene was identified as a semiconductor with a narrow energy gap (< 0.05 eV).
• These findings clarify the phase composition and electronic nature of Ba-doped phenanthrene superconductors.