Strain Control of Giant Magnetic Anisotropy in Metallic Perovskite SrCoO 3-δ Thin Films.

Magnetic materials with large magnetic anisotropy are essential for workaday applications such as permanent magnets and magnetic data storage. There is widespread interest in finding efficient ways of controlling magnetic anisotropy, among which strain control has proven to be a very powerful technique. Here, we demonstrate the strain-mediated magnetic anisotropy in SrCoO _3-δ thin film, a perovskite oxide that is metallic and adopts a cubic structure at δ ≤ 0.25. We find that the easy-magnetization axis in SrCoO _3-δ can be rotated by 90° upon application of moderate epitaxial strains ranging from -1.2 to +1.8%. The magnetic anisotropy in compressive SrCoO _3-δ thin films is huge, as shown by magnetic hysteresis loops rendering an anisotropy energy density of ∼10 ⁶ erg/cm ³ . The local variance in magnetic force microscopy upon temperature and magnetic field reveals that the evolution of magnetic domains in the SCO thin film is strongly dependent on magnetic anisotropy.