Figure 4.

Ferroelectric properties of a 170 nm thick BSMO film on Nb-STO. (a) Amplitude (triangle and blue line) and phase (square and red line) of the PFM signal as a function of bias voltage. (b) PFM phase contrast scan at RT on BSMO after −5 V writing (5 × 5 μm²), 5 V rewriting (3 × 3 μm²), and −5 V rewriting (1 × 1 μm²) at RT, directly after writing (left), and after 72 h (right).