Spin-orbit coupling induced structural stability and semi-metallic state in La3 Ir3 O11

La3 Ir3 O11 crystallizes in a cubic symmetry with its structure composed of electronically active IrO6 octahedral motifs, which are corner and edge shared. Empirical considerations suggest Ir to be in the +4.33 valence state in La3 Ir3 O11, thereby anticipating the material to be a good conductor primarily due to the presence of holes in the crystal field split t2g bands of the Ir 5d manifold. However, a comprehensive investigation of the electronic structure by means of first principles calculations find La3 Ir3 O11 to be a spin-orbit driven semi-metallic iridate, with its Fermi energy comprised of both hole and electron bands. The properties of the electron-hole asymmetry in La3 Ir3 O11 is clearly manifested in the temperature dependent variation of electrical conductivity and Seebeck coefficient, which are calculated using the Boltzmann transport theory. Besides, finding that Fermi energy is positioned in a steep valley like feature in the density of states spectra, the calculations also predict that both hole and electron doping would induce a semi-metal to metal transition in La3 Ir3 O11.