8 - Interface engineering in oxide heterostructures for novel magnetic and electronic properties

Abstract

The past decades have witnessed intense research activity in ultra-thin magnetic multilayers/superlattices, which led to the development of high-density magnetic recording media and magnetic sensors. A recent breakthrough in the precise engineering techniques of ultra-thin films and oxide heterostructures promotes the research interests to extend the furtherance of novel characterization of materials and the fabrication of highly efficient non-volatile memory devices. In the perspective of memory devices, complex metal oxides are one of the potential compounds for constructing devices where varieties of magnetic and electronic properties are found in the bulk and ultra-thin films due to the strong correlations among electronic charge, spin, and orbital degrees of freedom. Besides, complex oxide heterostructures enrich novel magnetic responses such as RKKY interaction, polar metallic states, Dzyaloshinskii-Moriya interaction, perpendicular magnetic anisotropy, spin-polarization, etc., that are emerged by varying the thickness of the nonmagnetic spacer, surface termination, and interface modified electronic states. Further, interfaces of oxide-based nonmagnetic-ferromagnetic metallic stacks induce the breaking of structural inversion symmetry, leading to the spin-orbit coupling phenomenon. Spin-orbit coupling phenomenon is responsible to show an extensive magnetic phenomenon associated with other physical phenomena such as ferroelectricity, superconductivity, topological Hall Effect, formation of magnetic skyrmions, etc., in both ultra-thicknesses and heterostructures. Therefore, in this chapter, we review the state-of-art possible various interfacial engineering techniques employed in understanding the electronic mechanisms and the magnetic properties in the complex oxide-based thin films and heterostructures.