Prediction for high superconducting ternary hydrides below megabar pressure

Area of Science:

• Materials Science
• Condensed Matter Physics
• Superconductivity Research

Background:

• High-temperature hydrides have advanced superconductivity research.
• Existing hydrides require extremely high pressures for stability.
• Need for superconductors stable at more accessible pressures.

Purpose of the Study:

• To investigate hydrides with UH8 and UH7 structures for superconductivity.
• To identify compounds with high critical temperatures (Tc) below 100 GPa.
• To determine the dynamic and thermodynamic stability of predicted compounds.

Main Methods:

• Extensive computational simulations.
• Calculation of superconducting critical temperatures (Tc).
• Formation enthalpy calculations for thermodynamic stability assessment.

Main Results:

• CeBeH8 predicted to be dynamically stable at 30 GPa with Tc of 201 K.
• ThBeH8 predicted to be dynamically stable at 10 GPa with Tc of 98 K.
• ThBeH7 predicted to be dynamically stable at 20 GPa with Tc of 70 K.
• Thermodynamic stability calculations indicate CeBeH8 is stable above 50 GPa and ThBeH8 above 88 GPa.
• ThBeH7 is thermodynamically stable above 33 GPa.

Conclusions:

• Identified novel hydride compounds (CeBeH8, ThBeH8, ThBeH7) with potential for high-temperature superconductivity.
• These compounds show promise for achieving superconductivity at significantly lower pressures than previously known hydrides.
• Results guide the future design of high-temperature superconductors at moderate pressures.