Superconducting ternary hydrides in Ca-U-H under high pressure

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• Hydrogen-rich ternary compounds are key to achieving superconductivity at lower pressures.
• The Ca-U-H system is investigated for its potential superconducting properties.

Purpose of the Study:

• To predict and analyze the crystal structures, electronic properties, and superconductivity of ternary Ca-U-H compounds.
• To explore the feasibility of synthesizing new superconducting materials.

Main Methods:

• Crystal structure prediction using high-throughput screening.
• Ab initio calculations to determine electronic structures and phonon properties.
• Density Functional Theory (DFT) for electron-phonon coupling analysis.

Main Results:

• Four dynamically stable Ca-U-H structures were identified, including CaUH12, Ca2UH18, and CaU3H32.
• Ca2UH18 and CaU3H32 are predicted to be synthesizable below 1 megabar.
• The superconducting transition temperature (Tc) for Ca2UH18 was estimated at 57.5–65.8 K at 100 GPa.

Conclusions:

• Introducing actinides like Uranium into alkaline-earth metal hydrides is a promising strategy for designing novel superconductors.
• The findings pave the way for discovering new materials with high-temperature superconducting properties.