Magnetic phase transition in mott-insulating ferrimagnetic Lu2NiIrO6

Using the first-principles density functional approach, here, we investigate electronic and magnetic
properties of newly discovered double perovskite Lu2NiIrO6 under the cooperative effect of
Coulomb interaction (U) for Ni-3d and Ir-5d elements and spin orbit coupling (SOC). This system
is ferrimagnetic (FIM) and half-metallic (HM) ground state in generalized gradient approximation
(GGA) and GGA+U, whereas SOC breaks HM and changes it into Mott-insulator with the band gap
of 0.19 eV in close agreement with experimental band gap in the (010)-direction. When Ni is
replaced with Fe, it’s magnetic ground state changes into anti-ferromagnetic (AFM) state with zero
spin magnetization in the unit cell and 1.0 eV band gap in the (100)-direction. Similarly, if Ir-5d
element is replaced with Ru-4d element, its FIM ground state remains unchanged with band gap of
0.47 eV in the (100)-direction.