Thermodynamic stability and creation of large half-metallic gap in BaZrO3 via non-magnetic elements doping

Abstract

Stable ferromagnetic (FM) materials having large half-metallic (HM) spin gaps are the potential candidates for spin-based memory devices as they restrict the spin-flipping and provide high spin-filtering along with a size-able mean free path for spins. Herein, ab-initio calculations were performed to elucidate the impact of non-magnetic (Y = B, C, and N) elements doping at oxygen site on the physical characteristics of wide band gap BaZrO3 perovskite oxide. The structural stability of doped motifs is analyzed based on formation energetics using Convex Hull analysis and mechanical stability, which confirm the experimental realization of the materials at ambient pressure. The remarkable outcome of the present study is that C and N-doped systems exhibit HM FM behavior having an integral moment of 2.0 and 1.0 μB, where a large band gaps of 1.85 and 2.84 eV exist in the spin-minority channels, respectively. On the other hand, B-doped motif remains semiconductor with an energy gap of 1.18 eV despite the integral moment of 3.0 μB. Moreover, it is also predicted that Y-dopant 2p orbitals are mainly responsible for the conduction and magnetism in doped systems. Finally, the solidity of FM ground state of the doped systems is evaluated by comparing the total energies of FM and anti-ferromagnetic spin ordering by varying the distances between dopants, which revealed that long range FM clustering is favorable in all doped systems. However, a most stable FM state is evident when the distance between two dopants is small (4.18 Å), which is due to a strong Y–Y FM interactions.