Search for thermodynamically stable ambient-pressure superconducting hydrides in the GNoME database

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Hydrides are promising for high-temperature superconductivity, but ambient-pressure superconducting hydrides with critical temperatures above 10 K are rare.
• Many predicted high-temperature superconducting hydrides exist in thermodynamically unstable phases.

Purpose of the Study:

• To identify thermodynamically stable hydride superconductors at room pressure.
• To assess superconducting properties of stable hydrides using computational methods.

Main Methods:

• Utilized the GNoME material database containing thousands of stable hydrides.
• Employed a multi-stage approach combining machine learning and ab initio calculations.
• Calculated superconducting critical temperatures (Tc) for stable hydride phases.

Main Results:

• Identified 25 cubic hydrides with critical temperatures (Tc) above 4.2 K.
• Achieved a maximum calculated Tc of 17 K among the stable hydrides.
• The identified stable hydrides are potentially experimentally accessible.

Conclusions:

• This study provides a list of stable hydride superconductors with modest but experimentally relevant critical temperatures.
• The findings suggest potential technological applications for these stable superconducting hydrides.