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We have investigated how the surface magnetism of epitaxial La 0.67 Sr 0.33 MnO 3 films on NdGaO 3 substrates is modified by 2 nm-thick caps of the undoped manganite LaMnO 3 and the band insulator SrTiO 3 . Low-temperature photoemission electron microscopy images with x-ray magnetic circular dichroism contrast reveal large ferromagnetic domains, and a reduction of surface Curie temperature by 40 K (LaMnO 3 cap) and 70 K (SrTiO 3 cap). We use these negative results to argue that capped films of sub-optimally doped La 1− x Sr x MnO 3 ( x ≠0.33) should improve the operating temperature of all-oxide and other spintronic devices.

Repeatable magnetization reversal under purely electrical control remains the outstanding goal in magnetoelectrics. Here we use magnetic force microscopy to study a commercially manufactured multilayer capacitor that displays strain-mediated coupling between magnetostrictive Ni electrodes and piezoelectric BaTiO(3)-based dielectric layers. In an electrode exposed by polishing approximately normal to the layers, we find a perpendicularly magnetized feature that exhibits non-volatile electrically driven repeatable magnetization reversal with no applied magnetic field. Using micromagnetic modelling, we interpret this nominally full magnetization reversal in terms of a dynamic precession that is triggered by strain from voltage-driven ferroelectric switching that is fast and reversible. The anisotropy field responsible for the perpendicular magnetization is reversed by the electrically driven magnetic switching, which is, therefore, repeatable. Our demonstration of non-volatile magnetic switching via volatile ferroelectric switching may inspire the design of fatigue-free devices for electric-write magnetic-read data storage.