SUMMARY

Patterning of high aspect ratio piezoelectric materials is important due to numerous applications such as actively tunable photonic crystals, energy harvesters, nano/micro fluidics, and high-resolution ultrasounds. The most technologically relevant piezoelectric material is lead zirconate titanate (PZT) due to its large piezoelectric coefficients, which induces a very strong direct and converse piezoelectric response. Current top-down methods used to pattern PZT films include material removal via a high energy beam, which damages the piezoelectric material, and wet etching, which is an isotropic process that results in poor edge definition. Similarly, current bottom-up approaches such as hard template-growth and hydrothermal processing have limited control over the aspect ratio of the structures produced on a single substrate, in addition to lack of site specific registry. In this work, a bottom-up approach for creating PbZr0.52Ti 0.48O3 nanotubes was developed using soft-template infiltration of a sol-gel solution. This method allows great control of the design of the piezoelectric structures produced on a single substrate with sub-micron detail, overcoming current manufacturing limitations. Thus far, nanotubes with aspect ratios from 1:1 up to 4:1 with lateral dimensions smaller than 100 nm have been produced. Along with the development of this new patterning scheme, this thesis investigates nanoscale phenomena exhibited in ferroelectrics as they scale in size.