First-principles study of magnetoelectric properties enhanced by lattice-domain modifications

One of the most studied ferroelectric components in multiferroic composites is BaTiO₃ (BTO). The (001) surface of the BTO single crystal has two types of lattice domains, namely the a and c domains. Experimental studies show that an applied electric field modulates the distribution of lattice domains in BTO. However, most of theoretical analyses of BTO-based multiferroic composites focused on the magnetic modulation by the electrical polarization in a single domain. Here, we performed first-principles calculations on Co₂FeSi/BaTiO₃(001) heterostructures analysing magneto-electric (ME) constants and the magnetic anisotropy energy (MAE) by considering the spin-orbit coupling explicitly in the Kohn-Sham Hamiltonian. We will demonstrate that larger ME constants are achieved by considering lattice domain modification in BTO, where the MAE analysis reproduces experimental trends.