Density functional theory study of a new Bi-based (K1.00)(Ba1.00)3(Bi0.89Na0.11)4O12 double perovskite superconductor.

A new single-phase double perovskite superconductor (K 1.00 )(Ba 1.00 ) 3 (Bi 0.89 Na 0.11 ) 4 O 12 with a T c ∼ 31.5 K has been recently synthesized via the hydrothermal route. In the present study, we employ DFT (density functional theory) calculations to investigate the properties (structural, mechanical, electronic, Fermi surface, charge density) of this new superconductor. The calculated lattice constant is in good agreement with the experimental result. The elastic constants, bulk modulus, shear modulus, Young’s modulus, elastic anisotropy of crystal, Peierls stress, and Debye temperature are calculated and used to explain the mechanical behavior of this newly synthesized perovskite. The calculated electron density of states (DOS) indicates strong ionic interactions that are present in the Na-O-Bi planes. Both the electron and hole like bands form the Fermi surface and exhibit the multi-band nature of the compound. The electron charge density map shows the isotropic nature of charge distribution. [ABSTRACT FROM AUTHOR]