Electronic and Magnetic properties of nitrogen substituted cubic perovskites of RbNbO3 and CsNbO3 using PBE-GGA and TB-mBJ methods

Abstract

ABSTRACT The electronic and magnetic properties are investigated for the nitrogen-substituted cubic perovskites of rubidium and caesium niobate compounds (RbNbNxO3-x and CsNbNxO3-x, using the first-principles method. The electronic properties such as half metallic ferromagnetism as improved by TB-mBJ exchange-correlation scheme are compared with GGA-PBE functional using Full-Potential Linearised Augmented Plane Wave (FP -LAPW) method. The nitrogen-substituted compounds RbNbNO2 and CsNbNO2 are found to be stable in ferromagnetic phase. The TB-mBJ approach predicts a larger half metallic gap in the spin-up channel as compared to GGA-PBE approach. Equal magnetic moments observed in both the exchange correlation methods highlight the ferromagnetic behaviour of the doped compounds. The half metallic ferromagnetism is triggered primarily due to doping of nitrogen.