“…Insets show the region directly affected by the SS-PFM measurement, where the reorientation of polarization with the applied electric field is observed, due to an indirect piezoelectric effect. White regions correspond to positive polarization domains (P z ), dark violet regions correspond to polarization in-plane (P x ) towards the bottom electrode, while yellow regions correspond to a remanent polarization; thus, an evident reorientation of polarization is achieved as found by many authors with this technique [ 17 , 18 , 19 , 58 , 59 ]. The hysteresis loop from switching polarization domains at a phase difference of 180° using AC voltage is presented in Figure 1 e. The amplitude (nm) versus bias voltage (V) plot in Figure 1 d exhibits a butterfly loop related to local deformation under the applied bias, which demonstrates polarization in granular domains, as described by Roelofs et al [ 60 ].…”