fig1

Figure 1. (A) χ-2θ diffraction images around the o-(111) reflection for HZO films of the indicated thickness for the three series: STO(001) O₂, STO(110) O₂, and STO(110) O₂/Ar. The orthorhombic (o) and monoclinic (m) reflections are indicated. (B) Area ratio of the m-(-111) diffraction peak with respect to the o-(111) peak, extracted from the χ-integrated 2θ patterns, as a function of film thickness for the three series of samples. (C) Schematic illustration of the thickness-dependent phase evolution of epitaxial HZO films, showing the stabilization of the orthorhombic phase in the ultrathin regime and the progressive appearance of the monoclinic phase with increasing thickness.