Strain-driven lattice distortion and the resultant magnetic properties of La0.7Sr0.3MnO3/BaTiO3 superlattices

We report on the artificial manipulation of interfacial magnetism in the superlattices (SLs) of ([La0.7Sr0.3MnO3]30/[BaTiO3]25)n (1 ≤ n ≤ 10) fabricated by pulsed laser deposition. The thicker 30 uc-La0.7Sr0.3MnO3 and 25 uc-BaTiO3 layers are designed as a single period of SLs in order to eliminate the interaction between two adjacent interfaces that could contribute to a polar phase transition and the corresponding magnetism. We use aberration-corrected scanning transmission electron microscopy and electron energy-loss spectroscopy to demonstrate that epitaxial-strain-driven lattice distortion renders the emergence of divalent Mn at the La0.7Sr0.3MnO3/BaTiO3 interfaces. The saturated magnetization decreases and the magnetic easy axis becomes more in-plane inclined as the interfacial strain of the SLs increases.