Giant strain in PbZr0.2Ti0.8O3 nanowires

The authors report a giant reversible piezoelectric strain of ∼4.2% achieved with single-crystalline PbZr0.2Ti0.8O3 nanowires of ∼70nm in diameter, which is nearly 300% greater than the nominal values reported for ceramic perovskite single crystals. The giant strain arises from the reversible switching of ferroelastic domains. In the nanowires, there is a competition between surface tension, which forces in-plane polarization, and applied electric field, which stabilizes out-of-plane polarization, through the entire voltage cycle, the result of which is the reversible movement of ferroelastic domains.