Superconductivity in Heusler compound ScAu₂Al

Area of Science:

• Condensed Matter Physics
• Materials Science
• Superconductivity

Background:

• Heusler compounds are a promising class of materials for superconductivity.
• Understanding the factors influencing superconducting transition temperature (Tc) is crucial for discovering new superconductors.

Purpose of the Study:

• To investigate the superconducting properties and electronic structure of the full Heusler material ScAu2Al.
• To determine the electron-phonon coupling strength and its correlation with superconductivity in ScAu2Al.

Main Methods:

• Resistivity measurements to determine the superconducting transition temperature (Tc).
• Magnetization measurements to characterize the superconducting state (e.g., type-II superconductivity, critical fields).
• Specific heat measurements to confirm bulk superconductivity.
• Electronic structure calculations to identify key features like van Hove singularities.

Main Results:

• ScAu2Al exhibits superconductivity with a Tc of 5.12 K, higher than previously reported.
• The material behaves as a moderate type-II superconductor with evidence of flux jumps.
• A sharp jump in specific heat confirms bulk superconductivity.
• The electron-phonon coupling constant (λe-ph) is determined to be 0.77, the highest among Heusler superconductors.
• Electronic structure calculations reveal a van Hove singularity near the Fermi level.

Conclusions:

• ScAu2Al is a significant Heusler superconductor with a high Tc.
• Electron-phonon coupling is strongly correlated with Tc in Heusler superconductors.
• The identified van Hove singularity may contribute to the observed superconducting properties.