Possible Half-Metallic Ferromagnetism in Rare-Earth Metals Based Ruthenate Double Perovskites: Ba2RERuO6 (RE = Dy, Tm)

Herein, a systematic mechanism behind long-range ferromagnetic (FM) ground state is described based on 4d-4f interactions demonstrated in strongly correlated Ba2DyRuO6 and Ba2TmRuO6 double-perovskite (DP) systems. Density functional theory (DFT) + U based possible half-metallic FM nature of the considered DPs is realized along with integer values of spin magnetic moments (8.0 and 3.0 mu(B) f.u.(-1), respectively). This robust FM configuration is mainly dependent on Ru5+ and rare-earth (RE3+) elements highlighting the importance of B-site cationic ordering approach used in present study. The optical response of considered rare-earth ruthenate DPs is also scrutinized, implying their potential usage in optical filter devices. The DFT + U based results are validated via comparing with existing experimental literature. This study suggests Ba2DyRuO6 and Ba2TmRuO6 as a novel addition to the family of half metals and will surely pave the way for materialists to experimentally explore their physical features for spintronic usage.