Electron-phonon coupling of the Ti₃Sb compound

Using the first-principles method based on density functional theory, we investigate the electronic, mechanical, phononic, superconducting, and topological properties of the A15 superconductor Ti 3Sb with/without the inclusion of spin-orbit coupling (SOC). We find that the calculated elastic constants satisfy the Born stability criteria and the ductile nature of Ti 3Sb. The result of phonon calculations reveals that the P m 3 ¯ n structure is dynamically stable. Sb atoms are dominated in the low-frequency region due to the mass difference between Ti and Sb from partial phonon calculations. Our electronic structure calculations show that Ti 3Sb has metallic band structures with Ti- d bands near the Fermi energy. The electron-phonon coupling constant (λ ≃ 0.80) indicates that Ti 3Sb has strong electron-phonon coupling. The critical temperature (T c μ = 0.10) is found to be 6.24 and 6.56 K with and without the SOC effect, respectively. Due to Ti's relatively small SOC strength, we do not find evidence of non-trivial topology in contrast to Ta compounds such as Ta 3Sb.