First-principles exploration of superconductivity in MXenes

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid-State Chemistry

Background:

• MXenes are a novel class of two-dimensional materials with a M-X-M layered structure.
• Superconductivity in two-dimensional materials is a key area of condensed matter physics research.
• Systematic exploration of superconductivity in MXene families is crucial for discovering new functional materials.

Purpose of the Study:

• To systematically investigate superconductivity in a wide range of MXene materials.
• To identify novel superconducting MXenes using first-principles calculations and theoretical formalisms.
• To characterize the superconducting properties and potential competing phases in these materials.

Main Methods:

• Utilized first-principles calculations to characterize material properties.
• Employed the Eliashberg formalism to study electron-phonon coupling and superconductivity.
• Screened various transition metal carbides and nitrides for superconducting behavior.

Main Results:

• Identified six superconducting MXenes: Mo2C, W2C, Sc2C (carbides) and Mo2N, W2N, Ta2N (nitrides).
• Determined the highest critical temperature (Tc) of approximately 16 K for Molybdenum nitride (Mo2N).
• Observed competing superconducting and charge density wave phases in Tungsten nitride (W2N).

Conclusions:

• The study expands the family of known superconducting MXenes.
• Mo2N shows promising superconducting properties with a Tc of ~16 K and established synthesis methods.
• W2N presents an interesting interplay between superconductivity and charge density waves, warranting further investigation.