Physical properties and electronic structure of Ir based ordered double perovskites La2MIrO6 (M = Mg, Zn).

We report the structural and magnetic properties along with the electronic structure of ordered double perovskites La2MIrO6 (M = Mg, Zn). An antiferromagnetic ordering below TN ∼ 12 K and weak ferromagnetic ordering below Tc ∼ 9 K is observed in La2MgIrO6 and La2ZnIrO6, respectively. A small hysteresis loop along with non-saturating magnetization even at large magnetic field suggests a canted-antiferromagnetic ground state in La2ZnIrO6. The valence band photoemission spectra at room temperature exhibit zero intensity at the Fermi level (EF), while density functional theory (DFT) calculation within local density approximation (LDA) suggests a metallic ground state. A rigid shift was observed in the O 2p band position in the experimental spectra compared to LDA results. These results suggest the importance of electron correlation in the ground state properties of these systems. [ABSTRACT FROM AUTHOR]