Fig. 1. (a) The sketch diagram of LSCMO/LSMO/LSCMO (x = 0–0.7) trilayers. (b) The surface morphology of the LSCO/LSMO/LSCO trilayer; the scale of the image is 5 × 5 μm². (c) The x-ray diffraction patterns of LSCMO/LSMO/LSCMO trilayers. The multi-peaks indicate the high crystal quality of the trilayers. The reciprocal space mappings of the (1¯03) reflections of (d) LSCO/LSMO/LSCO and (e) LSCMO/LSMO/LSCMO (x = 0.7) trilayers.

Fig. 2. Typical high-angle annular dark-field image of the cross-section of the LSCMO/LSMO/LSCMO trilayers with (a) x = 0, (b) x = 0.3, and (c) x = 0.7, respectively, recorded along the [100] zone. Red dashed-line marks the LSCMO/LSMO interface and the yellow arrows represent the dark stripes.

Fig. 3. Thermomagnetic curves of the (a) LSCO/LSMO/LSCO and (b) LSCMO/LSMO/LSCMO (x = 0.7) trilayers. The data were acquired in field-cooling mode with in-plane or out-of-plane applied fields. Blue and orange areas highlight the difference of the magnetic moments along two measuring directions. The moment as a function of applied fields for the (c) LSCO/LSMO/LSCO and (d) LSCMO/LSMO/LSCMO (x = 0.7) trilayers, extracted from the thermomagnetic data at T = 10 K. The shaded area corresponds to the energy required to orientate the magnetic moment of trilayer from the hard axis to the easy axis.

Fig. 4. (a) Thermomagnetic curves of the LSCMO/LSMO/LSCMO (x = 0–0.7) trilayers along the in-plane and out-of plane directions under an applied field of 0.05 T. (b) The K_A as a function of temperature for the LSCMO/LSMO/LSCMO (x = 0–0.7) trilayers. Here, the positive value of K_A indicates the perpendicular magnetic anisotropy. (c) The K_A as a function of Mn concentration for the LSCMO/LSMO/LSCMO (x = 0–0.7) trilayers at 10 K. The blue curve and light green curve are the results extracted from thermomagnetic curves and hysteresis curves, respectively.

Fig. 5. Normalized Mn-XAS spectra for the (a) [LSCO(4 uc)/LSMO(4 uc)]₅ and (b) [LSCMO(4 uc)/LSMO(4 uc)]₅ (x = 0.7) multilayers, measured with the optical polarization parallel (E||a, I_IP) or perpendicular (E||c, I_OP) to the film plane. The sketch shows the experimental setup. Bottom panels are the corresponding XLD spectra and the shaded areas provide the information on orbital occupancy. The arrow marks the spin orientation of the LSMO layer.