Magnetoelectric, and dielectric based switching properties of co-doped BiFeO3 for low energy memory technology: a first-principles study

Abstract

First-principles calculations are carried out to grow half-metallicity, tune dielectric and magnetoelectric properties of pure and doped bismuth ferrite BiFeO3 (BFO) with lanthanum (La) at A-site and cobalt (Co) at B-site as mono- and co-dopants. These calculations are performed in the Cambridge Serial Total Energy Package (CASTEP) code using ultra-soft pseudopotential (USP). A large band gap has been observed in the pure rhombohedral phase. The Co impurity atom is more favorable to decrease the band gap while La pushes the BFO towards half-metallic behavior, which develops 100% polarization in all doped BFO systems. From the dielectric response of BFO, high spin current density <s> of 8.7 × 103 A/m2 and charge current density (j) of 6.3 × 10–11 A/m2 have been observed in the La doped system. In the case of magnetic properties, the strong magnetization (M) 32.13 MA/cm2 and the large magnetoelectric coupling coefficient of 6.72× 10−6 s/m have been observed in co-doped BFO.