Enhanced superconducting transition temperature via alloying In, Sn and Sb in PbH4 by using first-principles calculations

The effects of In, Sn and Sb alloying in PbH4 on the superconductivity at high pressure are investigated via the first-principles calculations, owing to alloying is an important method to improve superconductivity. By calculating the formation enthalpy, elastic constants and phonon dispersion, it is indicated that the alloying structures satisfy the thermodynamical, mechanical and dynamic stability, respectively. The superconductivity of the Pb2MH12 (M = In, Sn and Sb) improved due to the addition of M. The superconducting transition temperature of the PbH4 is 62 K, and the values for Pb2MH12 (M = In, Sn and Sb) are increased to 70, 69 and 66 K, respectively. The calculations of the electronic structure and electron-phonon coupling show that the contribution of H atoms to the density of states at the Fermi energy increases, and the strength of electron-phonon coupling is enhanced. The results indicate that the alloying of lighter elements and lower electronegativity is an effective method to improve superconducting properties.

Automated summary

The effects of In, Sn, and Sb alloying in PbH4 on the superconductivity at high pressure were investigated using first-principles calculations. The alloying structures exhibited thermodynamical, mechanical, and dynamic stability, as indicated by the calculated formation enthalpy, elastic constants, and phonon dispersion. The superconductivity of Pb2MH12 (M = In, Sn, and Sb) was improved by the addition of M. The superconducting transition temperature increased from 62 K for PbH4 to 70, 69, and 66 K for Pb2MH12 (M = In, Sn, and Sb), respectively. Electronic structure and electron-phonon coupling calculations showed an increase in the contribution of H atoms to the density of states at the Fermi energy and enhancement of the strength of electron-phonon coupling. The results suggest that alloying lighter elements with lower electronegativity is an effective method to improve superconducting properties.