Stable Structures and Superconductivity in a Y-Si System under High Pressure

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Superconductivity in compressed electrides is a recent discovery offering new avenues for high-temperature superconductivity research.
• The limited number of known superconducting electrides restricts the exploration of their diverse properties.

Purpose of the Study:

• To explore the Y-Si system under high pressure for novel superconducting materials.
• To identify stable stoichiometries and structural configurations in the Y-Si system.

Main Methods:

• Utilized the CALYPSO structure prediction methodology for extensive structure searches.
• Performed simulations on the Y-Si system under high-pressure conditions.

Main Results:

• Identified several stable Y-Si stoichiometries: YSi, YSi2, YSi3, Y5Si3, Y2Si, and Y3Si.
• Observed diverse silicon structural configurations, including chains, rings, and layers.
• Predicted Y3Si as an electride superconductor with critical temperatures of ~11.2 K at 30 GPa and ~14.5 K at 50 GPa.

Conclusions:

• The study expands the known examples of superconducting electrides.
• The findings emphasize the significance of Fermi surface electrons in electride superconductivity.
• This research provides a new high-pressure superconducting electride candidate for further investigation.