As the depth profile scans progressed, we aligned each Zr 3d peak in every scan to the Zr 3d peak at the final scan to calibrate all peaks. This approach aimed to minimize any peak shifting during Ar + sputtering, although the actual shifting observed was minimal (<0.1 eV). Notably, the XPS depth profiles of Ag 3d, Zr 3d, and La 3d without aligning Zr 3d peaks (Figure ) showed negligible shifting and yielded identical results to those in Figure .