Figure 3: Unipolar BEPS switching loops of 50 nm BFO/STO.
From: Giant elastic tunability in strained BiFeO3 near an electrically induced phase transition
(a–f) Unipolar BEPS loops acquired under negative (a–c) and positive (d–f) tip biases at the same location. The on-field loops are in red/blue and the off-field loops in black/cyan. Light blue and purple shadowed areas are guides to eyes indicating the in-plane switching (IPS) and R−T transition regions, respectively. Dashed lines in c,f denote the second harmonics response signal noise floor. (g,h) Single-point strain curves (g) and its derivative (that is, static d33) loops versus corresponding on-field piezoresponse loops (h). (i) Histogram of the static d33 loops calculated from 40 × 40 strain curves acquired over a 1 × 1 μm2 region, via a 6th-order polynomial fitting to the measured data as illustrated in g. a.u., arbitrary unit.
