Perpendicular magnetic anisotropy induced by La2/3Sr1/3MnO3-YBaCo2O5+δ interlayer coupling

Heterostructure with a symmetry-mismatched interface provides a promising playground for the exploration of emergent phenomena. Herein, we report a systematic investigation on La2/3Sr1/3MnO3/YBaCo2O5+delta (LSMO/YBCO) grown on SrTiO3, a heterostructure formed by perovskite oxides of different symmetry. A high-resolution lattice image shows the formation of high-quality perovskite LSMO and A-site cation-ordered oxygen-deficient double perovskite YBCO, without any signatures of atomic reconfiguration at the interface. Surprisingly, the YBCO-buffered LSMO exhibits perpendicular magnetic anisotropy (PMA), though bare LSMO film is in-plane anisotropic. The PMA is robust, appearing even when the thickness of YBCO is only one unit cell. The typical anisotropy constant is similar to 4 x 10(6) erg cm(-3). X-ray absorption spectroscopy analysis reveals a preferential occupation of the d(3z2-r2dx2-y2), which is confirmed by density functional theory calculations. This orbital reconstruction accounts for the PMA. The formation of a covalent bond between Mn and Co caged by different oxygen polyhedrons, an octahedron and a square pyramid, respectively, stabilizes the orbital reconstruction, resulting in anomalous spin orientation.

Automated summary

The research reports on the growth behavior of heterostructures formed on interfaces with symmetry mismatch, specifically focusing on the growth of La2/3Sr1/3MnO3/YBaCo2O5+delta (LSMO/YBCO) on SrTiO3. High-quality crystal structures of LSMO and YBCO were observed without any atomic rearrangement at the interface. Surprisingly, LSMO buffered by YBCO shows perpendicular magnetic anisotropy (PMA) with robust stability, even with a thin YBCO layer. This phenomenon is attributed to orbital reconstruction and the formation of a covalent bond between Mn and Co caged by different oxygen polyhedrons.