New superconducting superhydride LaC₂H₈ at relatively low stabilization pressure

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• Recent experimental discovery of high-temperature carbonaceous sulfur hydride (C-S-H).
• Exploration of ternary compounds for high-pressure superconductivity.

Purpose of the Study:

• Systematically investigate the superconductivity of carbonaceous lanthanum hydride (C-La-H) ternary compounds.
• Identify potential high-temperature superconductors under high pressure.

Main Methods:

• First-principles calculations.
• Strong-coupling Migdal-Eliashberg theory.
• High-pressure phase stability analysis.

Main Results:

• Identified a novel ternary system, LaC2H8, with a clathrate structure (space group Fm-3m).
• Determined dynamic and thermal stability of LaC2H8 above 70 GPa.
• Calculated superconducting critical temperature (Tc) in the range of 69–140 K.

Conclusions:

• LaC2H8 is a promising candidate for high-temperature superconductivity.
• The findings contribute to the search for novel superconducting materials under extreme conditions.