Predictive Study of the Rare Earth Double Perovskite Oxide Ba2ErReO6 and the Influence of the Hubbard Parameter U on its Half-Metallicity

Abstract

In this paper, we have studied and carried out a theoretical calculation using the full-potential linearized augmented plane-wave method (FP-LAPW), based on density functional theory (DFT) and implemented in the wien2k program to investigate the structural, electronic, and magnetic properties of Ba2ErReO6 material, within the generalized gradient approximation (GGA) and generalized gradient approximation with effective Hubbard U parameter (GGA\u2009+\u2009U). According to the electronic properties and according to the GGA approximation, the results show that our material Ba2ErReO6 has a metallic character with integral magnetic moment of 5.1 µB; however, through employing the GGA\u2009+\u2009U method, the material Ba2ErReO6 radically changes in nature due to the fact that it presents a half-metallic character with a direct band gap at Γ-Γ direction in spin down channel and this for values of U\u2009≥\u20092\xa0eV; in addition, we see that the greater the Hubbard coefficient U, the greater the energy gap of the material in its semi-conducting nature (in the spin down channel) until reaching the value of 1.96\xa0eV corresponding to a value of 8\xa0eV for the Hubbard coefficient U. This is a predictive study of the double perovskite compound Ba2ErReO6 based on rare earths Er and therefore constitutes a serious reason for further theoretical investigations as well as adequate experiments and this for very useful and widespread applications such as spintronic, high-performance electronic devices, and optic applications.