Pressure-induced superconductivity of Ac-B-H hydrides

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• The quest for room-temperature superconductors is a significant challenge in materials science.
• High-pressure hydrides have emerged as promising candidates for high-temperature superconductivity.
• Understanding structure-property relationships in these materials is crucial for designing new superconductors.

Purpose of the Study:

• To investigate the structural, thermodynamic, and superconducting properties of ternary Ac-B-H hydrides.
• To identify stable hydride structures under high pressure.
• To predict the superconducting transition temperatures (Tc) of these hydrides.

Main Methods:

• Utilized a genetic algorithm (GA) for structure prediction.
• Employed density functional theory (DFT) calculations for stability and property analysis.
• Calculated electron-phonon coupling to determine superconducting transition temperatures.

Main Results:

• Identified two stable ternary Ac-B-H hydride structures: R3̄m-AcBH8 and I4/mmm-AcB2H8, stable above 70 GPa and 125 GPa, respectively.
• Calculated superconducting transition temperatures (Tc) of 140 K for R3̄m-AcBH8 at 70 GPa and 99 K for I4/mmm-AcB2H8 at 125 GPa.
• Found that electron-phonon coupling is strongly influenced by the vibrations of B-H bonds.

Conclusions:

• Ternary Ac-B-H hydrides are potential candidates for high-temperature superconductivity.
• The R3̄m-AcBH8 and I4/mmm-AcB2H8 structures exhibit promising superconducting properties under high pressure.
• Vibrations within the B-H bonds play a critical role in the electron-phonon coupling mechanism.