First-principles study on phase stability and physical properties of B-site ordered Nd$_{2}$FeCrO$_{6}$ double perovskite

Abstract: Here, the first-principles predictions on the structural stability, magnetic behavior and electronic structure of B-site ordered double perovskite Nd${2}$FeCrO${6}$ have been reported. Initially, the ground state of the parent single perovskites NdCrO${3}$ and NdFeO${3}$ have been studied to determine the relevant Hubbard U parameter to investigate the properties of Nd2CrFeO6. The thermodynamic, mechanical, and dynamic stability analyses suggest the possibility of the synthesis of Nd${2}$FeCrO${6}$ double perovskite at ambient pressure. The compound shows ferrimagnetic (FiM) nature with 2 $\mu$B net magnetic moments and the magnetic ordering temperature has been estimated to be $\sim$265 K. Electronic structure indicates higher probability of direct photon transition over the indirect transition with a bandgap of $\sim$1.85 eV. Additional effect of Nd (4f) spin and spin-orbit coupling (SOC) on the band edges have been found to be negligible for this 4f-3d-3d spin system. This first-principles investigation predicts that due to the ferrimagnetic nature and significantly lower bandgap compared to its antiferromagnetic parent single perovskites, B-site ordered Nd${2}$FeCrO${6}$ double perovskite could be a promising material for spintronic and visible-light-driven energy applications.