Figure 2
From: Unveiling the piezoelectric nature of polar α-phase P(VDF-TrFE) at quasi-two-dimensional limit
Piezoelectric hysteresis loops of the quasi-two-dimensional α-phase P(VDF-TrFE) films on AlOx/Al substrates. (a) Local PFM phase curves with an unambiguous 180° phase shift. The insets show the molecular structures corresponding to the two polarization states. (b) Local PFM amplitude curves with an expected classical butterfly shape. The insets show the stretched and compressed configurations of the α-phase P(VDF-TrFE). Hysteresis loops are recorded with three different sweep voltages of ±3 V, ±5 V, and ±7 V; the sweep direction is indicated by the arrows.
