Out-of-plane magnetic anisotropy enhancement in La1−xSrxCoO3−δ/La2/3Sr1/3MnO3/La1−xSrxCoO3−δ thin films

Perpendicular magnetic anisotropy (PMA) in multilayer thin films promotes the development of spintronic and magnonic research fields. The origin of the PMA deserves a thorough investigation since it contains rich physics related to multiple factors in the heterostructure system. Here, we study the origin of PMA in $\mathrm{L}{\mathrm{a}}_2/3\mathrm{S}{\mathrm{r}}_1/3\mathrm{Mn}{\mathrm{O}}₃$ (LSMO) thin films sandwiched by $\mathrm{L}{\mathrm{a}}_{1\ensuremath{-}x}\mathrm{S}{\mathrm{r}}_x\mathrm{Co}{\mathrm{O}}_{3\ensuremath{-}\ensuremath{\delta}}$ (LSCO) layers grown on $\mathrm{SrTi}{\mathrm{O}}₃$ substrate, using aberration-corrected scanning transmission electron microscopy. Our findings indicate that the lattice and electronic structures of LSMO can be modified through the inhomogeneous strains induced by nanodomains in LSCO layers. Moreover, we infer that the lattice distortion in LSCO at low temperatures is a driving force to reorient the spin moment from in-plane direction to out-of-plane direction in LSMO, which could be the nature of the PMA formation. The symmetry breaking in the LSMO layer induced by the domains from LSCO enhances magnetic anisotropy energy in LSMO.