Electric field-controlled reversible high-temperature perpendicular magnetic anisotropy in cobaltate–manganite heterostructures

Abstract

Electric field-controlled perpendicular magnetic anisotropy (PMA) in strongly correlated oxides can be a crucial technical strategy to realize ultralow-power-dissipation spintronic devices. In this report, we have overcome the major obstacle of the magnetic easy axis of La_0.7Sr_0.3MnO₃ (LSMO) films along the in-plane orientation owing to the effect of demagnetization. Herein, guided by first-principles calculations, we synthesized high-quality brownmillerite SrCoO_2.5 (SCO)/LSMO bilayer heterostructures on (001)-oriented SrTiO₃ substrates. Magnetism and magneto-transport measurements reveal that the LSMO layer exhibits an obvious preferential out-of-plane magnetic anisotropy in the bilayer structure, which is completely different from the in-plane magnetic easy axis in a single LSMO film. Specifically, the robust PMA is sustained up to 250 K, which is higher than the PMA in SrRuO₃ films. In addition, the results from the X-ray linear dichroism measurement confirm that the electron occupancy state of the LSMO layer in the bilayer structure are the out-of-plane 3z²–r² orbital. Furthermore, the electric field-reversible tunable high-temperature PMA of the LSMO layer is achieved by manipulating the phase transition in the top layer of B-SCO driven by ionic-liquid-gating. This work not only provides a special reversible high-temperature PMA material controllable by an electric field but also facilitates the development of manganite oxide-based electronic components.