Robust manipulation of magnetism in LaAO₃/BaTiO₃ (A = Fe, Mn and Cr) superstructures by ferroelectric polarization

Abstract

Robust control of magnetism is both fundamentally and practically meaningful and highly desirable, although it remains a big challenge. In this work, perovskite oxide superstructures LaFeO3/BaTiO3 (LFO/BTO), LaMnO3/BaTiO3 (LMO/BTO) and LaCrO3/BaTiO3 (LCO/BTO) (001) are designed to facilitate tuning of magnetism by the electric field from ferroelectric polarization, and are systemically investigated via first-principles calculations. The results show that the magnetic ordering, conductivity and exchange interactions can be controlled simultaneously or individually by the reorientation of the ferroelectric polarization of BTO in these designed superstructures. Self-consistent calculations within the generalized gradient approximation plus on-site Coulomb correction did not produce distinct rotations of oxygen octahedra, but there were obvious changes in bond length between oxygen and the cations. These changes cause tilting of the oxygen octahedra and lead to spin, orbital and bond reconstruction at the interface, which is the structural basis responsible for the manipulation. With the G-type antiferromagnetic (G-AFM) ordering unchanged for both ±P cases, a metal–insulator transition can be observed in the LFO/BTO superstructure, which is controlled by the LFO thin film. The LMO/BTO system has A-type antiferromagnetic (A-AFM) ordering with metallic behavior in the +P case, while it shifts to a half-metallic ferromagnetic ordering when the direction of the polarization is switched. LCO/BTO exhibits C-type antiferromagnetic (C-AFM) and G-AFM orders in the +P and −P cases, respectively. The three purpose-designed superstructures with robust intrinsic magnetoelectric coupling are a particularly interesting model system that can provide guidance for the development of this field for future applications.

Li-ion intercalation-driven control of two-dimensional magnetism in van der Waals FePS3 bilayers

“…Half-metallic materials, especially 2D half-metallic materials, can generate 100% spin-polarized currents without any external operation and thus play significant roles in spintronics. 62,63 Although the FePS 3 bulk 20,23 and bilayer are semiconductors, 48 our calculation results reflect the metallic and half-metallic behaviors of the 1Li-FPS and 2Li-FPS bilayers, respectively. Thus, we have successfully realized the semiconductor → metal/half-metal transition in the 2D FPS bilayer through the Li-ion intercalation scheme, which effectively promotes the application of 2D FPS materials in the high-performance information transmission field.…”

Magnetoelectric coupling effect of polarization regulation in BiFeO3/LaTiO3 heterostructures*

“…[3][4][5][6][7][8] However, single-phase multiferroics are quite rare at room temperature, because the ferromagnetic requires unpaired electrons in partially occupied d-orbitals or f-orbitals and ferroelectricity requires empty d-orbitals which is mutually exclusive in nature. [9][10][11] The ME coefficient is usually weak because there is associated with different ions, which is far from the application. Therefore, many researchers make a concerted effort to find the multiferroic composite materials and a study of the ME coefficient improvement at room temperature has become a research hotspot.…”

“…Heterogeneous multiferroics combining ferromagnetic and ferroelectric materials together can produce a strong magnetoelectric coupling effect. [9] Based on the heterostructures (HSs) of perovskite oxides, the FE and FM phases at the interface have been designed through advanced thin film material preparation technology to achieve the magnetoelectric coupling at the atomic scale. [12][13][14] Due to the strong correlation effect of d-orbital electrons, [15,16] the surface/interface of the HSs has lattice reorganization and electron reorganization which can produce a multi-degree-of-freedom interaction of "spin-orbit-charge-lattice", [1,6,[17][18][19] such as, transition between metal and insulator, magnetism, two-dimensional electron gas (2DEG), etc.…”