1：Experimental Design and Method Selection:

Nano-multilayers of BNT/LCMO were grown on LaNiO3 (LNO)-buffered SrTiO3 (STO) using stoichiometric ceramic targets by rf magnetron sputtering. The nano-multilayers with the total thickness of 280 ± 15 nm with 20 periodicities were fabricated with a periodicity of 8 nm/6 nm of ferroelectric layers (BNT)/magnetic sublayers (LCMO).

2：Sample Selection and Data Sources:

The substrates were cleaned ultrasonically in ethanol and acetone and dried with argon gas.

3：List of Experimental Equipment and Materials:

X-ray diffraction (XRD) using a D/max-rA X-ray diffractometer with Cu-Ka radiation, transmission electron microscopy (TEM, FEI Tecnai), RT66A standard ferroelectric test system, Semiconductor Testing System (Keithley 4200-SCS, USA), and Semiconductor Device Analyzer (Agilent B1500A, USA), scanning probe microscope (SPM) (MicroNano D5A), superconducting quantum interference device (SQUID).

4：Experimental Procedures and Operational Workflow:

The process involved deposition of a LaNiO3 buffer layer, followed by LCMO and BNT layers deposition under specific conditions, and annealing in O2 flow.

5：Data Analysis Methods:

Phase identification and crystal orientation by XRD, microstructure and phase structure by TEM, polarization-voltage, current-voltage, and capacitance-voltage properties measurement, switching of polarization by PFM, magnetic properties by SQUID, ME coupling characterization by ME measuring device.