Ferri-magnetic mott-insulating state in Lu2NiIrO6: Ab-initio study.

Iridium-based double perovskite oxides (DPO) provide a rich variety of multifunctional properties and technological applications due to their entangled spin-orbit coupling (SOC) state. Here, we theoretically investigated the electronic and magnetic properties of newly discovered Lu 2 NiIrO 6 DPO, in which both the electron correlation and the SOC play vital roles. Our results revealed that a strong antiferromagnetic superexchange interaction between Ni and Ir ions results in a ferrimagnetic ordering. Interestingly, the computed Curi temperature of 225 K is very close to the experimentally observed value of 207 K [Inorg. Chem. 58 , 397 (2019)]. Moreover, the system exhibits a Mott-insulating (energy gap mainly exists between 5 d -orbitals of Ir ion) behavior with an energy gap of 0.20/0.26 eV with/without SOC. The calculated total magnetic moments are 0.95 and 1.04 μ B /f.u. with and without SOC, respectively, which mainly arises from Ni ion and inclusion of SOC induced a substantial orbital moment of − 0.45 μ B /Ir. A combination of low/high energy band gap in the spin-majority/minority channel and substantial spin(orbital) moment makes the system an appealing candidate for spintronic applications. • Antiferromagnetic superexchange coupling leads the system to Ferrimagnetic ground state. • System exhibits a Mottinsulating behavior with an energy gap of 0.26 eV. • SpinOrbit coupling induced a substantial orbital moments on Ir atom. • System show a high Curie Temperature of 225 due to substantial octahedral distortion. [ABSTRACT FROM AUTHOR]