Ab initio investigation of physical properties of LaT2B2C (T=ir, Rh) compounds: A density functional theory approach

Abstract

The structural, electronic, lattice dynamical, and electron-phonon interaction properties of LaIr2B2C and LaRh2B2C crystallised in body-centred tetragonal structure are investigated by using the generalised gradient approximation of the density functional theory and the planewave pseudopotential method. The structural results are in good accordance with previous experimental studies. The electronic studies show that the density of states at the Fermi level of both borocarbide compounds are dominated by the d states of transition metal Ir(Rh). Also it is observed that the electron-phonon interaction in LaIr2B2C and LaRh2B2C are mainly carried out by the low-frequency phonon modes. By integrating Eliashberg spectral function, the superconducting transition temperature for LaIr2B2C and LaRh2B2C are obtained as 0.22 K and 0.20 K, respectively.