Superconducting properties and electronic structure of NaBi

Area of Science:

• Condensed Matter Physics
• Materials Science
• Superconductivity

Background:

• Superconducting materials are crucial for advanced technologies.
• Understanding the fundamental properties of novel superconductors like NaBi is essential.
• Investigating the interplay between electronic structure and superconductivity provides insights into material behavior.

Purpose of the Study:

• To experimentally characterize the superconducting properties of NaBi.
• To theoretically investigate the electronic structure of NaBi.
• To determine the electron-phonon coupling strength and classify NaBi's superconducting behavior.

Main Methods:

• Electrical resistivity measurements.
• DC magnetization measurements.
• Heat capacity measurements.
• First-principles electronic structure calculations.

Main Results:

• Superconducting transition temperature (Tc) of 2.15 K.
• Electronic specific heat coefficient (γ) of 3.4 mJ/mol·K².
• Debye temperature of 140 K.
• Electron-phonon coupling constant (λep) of 0.62, indicating moderate coupling.
• Upper critical field (Hc2) of 250 Oe and coherence length of 115 nm.
• Electronic structure calculations confirm NaBi as a good metal with Bi p-orbitals dominating states at the Fermi energy.

Conclusions:

• NaBi exhibits characteristics of a moderately coupled superconductor.
• Experimental results are consistent with theoretical electronic structure calculations.
• The electronic states at the Fermi energy are significantly influenced by Bismuth's p-orbitals.