1：Experimental Design and Method Selection:

The study employed magnetron sputtering at room temperature to deposit multilayers with composition Ta(3 nm)/Pt(4 nm)/Co(1 nm)/X(

2：2 nm)/MgO(t)/Pt(5 nm), where X is Ta or Mg. The effect of thermal annealing on the DMI was investigated by annealing samples at temperatures ranging up to 380 ℃. Sample Selection and Data Sources:

Samples with different MgO thicknesses (t = 0 to

3：0 nm) were prepared to examine the variance of DMI. List of Experimental Equipment and Materials:

An alternating gradient field magnetometers (AGFM) was used to confirm the perpendicular magnetization and characterize the magnetic properties. A Kerr microscope was employed to observe asymmetric domain-wall movement.

4：Experimental Procedures and Operational Workflow:

The strength of DMI was quantified by analyzing domain-wall motion in the presence of an in-plane field. The effective DMI fields were measured using a field-driven creep regime domain expansion method.

5：Data Analysis Methods:

The DMI constant was calculated using values of saturation magnetization (????) and effective anisotropy (????????) obtained from hysteresis loops, and the exchange stiffness constant (??) from literature.