Figure 1

Pulse width dependent switched behavior. (a) Pulse width dependence of the normalized switched area on the pulse amplitudes of +1.5 V (red circle), +2.0 V (black square), and +2.5 V (green inverse-triangle), respectively, in 70-nm-diameter PZT capacitors. The solid lines are guides for the eye. (b, c) PFM phase images (top) and their schematic domain structures (bottom) of instantaneous domain configurations developing at different pulse widths under applied biases of +2 V (after an initial background poling to the upward polarization) for pristine (b) mono-downward and (c) multi-polarized capacitors. The blue (red) arrows of (a) indicate the pinning (de-pinning) points. The blue solids of (b) and dashed lines of (b) and (c) indicate defect and capacitor boundary, respectively.