“…The clear pattern of cubic Pr 2 O 3 due to the two orthogonal cubic domains [4], appears only after the thickness reaches more than 2-3 nm, indicating that the interfacial layer is approximately 2 nm thick at this point. The typical interfacial layer thickness, grown under similar conditions, is reported as 1-2 nm in other works [2,4,11]. In the case of Si addition during growth, the crystalline diffraction pattern begins to appear at a thickness of 0.5 nm.…”