Atomic force microscopy of the substrate and film. Unit cell high vicinal steps were formed by annealing -plane substrates for at in air (a). After PLD and sputtering, the heterostructure replicated the unit cell steps (b). Profiles shown in the inset were taken perpendicular to the step edges. The crystallographic directions in (a) are identified by phi scan in x-ray diffraction.
MFA was performed in four different directions in the following order: relative to AFM crystallography, (a)  at and (b) at ; and relative to FM anisotropy axes, (c) hard axis at and (d) easy axis at , as shown by arrows. Finally, zero field annealing (ZFA) was performed to return to allow spin relaxation (f). The blue dotted line indicates the direction of vicinal step edges. There existed a residual even in the as-deposited sample (e). Note that all polar plots show a distinct fourfold anisotropy with origins most likely from FM/AFM in situ exchange coupling during sputtering.
Comparison of experimental data (in red) with the model fit (in green) for MFA parallel to . The cumulative effect and contribution of MFA, , and fourfold (in navy), , modeled the observed .
Varitation of and with MFA and ZFA.
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