fig17
![Microstructural evolution and ferroelectricity in HfO<sub>2 </sub>films](https://image.oaes.cc/acb286e2-3aef-4c4b-b87e-31f17f58d8a1/4637.fig.17.jpg)
Figure 17. (A) Plan-view SAED pattern and (B) representative cross-sectional STEM-HAADF image of a 4-nm-thick film. (C) Cross-sectional STEM-HAADF image from a 9-nm-thick HZO sample. (D) STEM-HAADF image observed along STO [100] (the STO substrate is not shown in the images), revealing an interfacial T-phase layer of HZO[29]. SAED: Selected-area electron diffraction; STEM-HAADF: scanning transmission electron microscopy-high angle annular dark-field; HZO: Hf0.5Zr0.5O2; STO: SrTiO3.