Search for ambient superconductivity in the Lu-N-H system

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• Recent claims of room-temperature superconductivity in N-doped lutetium hydride have spurred significant research interest.
• Understanding the phase diagram and potential superconducting properties of such hydrides is crucial for advancing materials science.

Purpose of the Study:

• To comprehensively investigate the phase diagram of the Lu-N-H system.
• To identify and evaluate potential superconducting phases within this system.
• To assess the viability of conventional superconductivity mechanisms in explaining reported phenomena.

Main Methods:

• Utilized ab initio crystal structure prediction combined with data-derived interatomic potentials.
• Sampled over 200,000 unique structures.
• Computed superconducting properties using Density Functional Perturbation Theory for 52 metastable candidates.

Main Results:

• Identified 52 metastable Lu-N-H structures within 50 meV of the convex hull.
• Predicted finite superconducting critical temperatures (T_c) for some structures.
• None of the predicted T_c values approach room-temperature superconductivity.

Conclusions:

• The comprehensive study of the Lu-N-H phase diagram did not yield evidence for room-temperature superconductivity.
• Conventional superconductivity mechanisms cannot explain the high T_c values previously reported for this material.
• This work contributes to the ongoing scientific effort to understand and verify claims of high-temperature superconductivity.