Nano-patterned PZT films for perspective functional materials

In this work, we describe the fabrication of PZT nanodisc arrays isolated by a polymer layer and contacted with a top electrode. PZT thin films were deposited by multi-target sputtering onto a platinum/titanium bottom electrode and structured by means of nanosphere lithography. To guarantee short-circuit-free evaporation of a top electrode, the space between the nanostructures was filled by a polymer. Two approaches for the filling are demonstrated: (i) imprinting and (ii) skim coating. Single nanodiscs embedded in a flexible polymer matrix have two major advantages. First, taking into account the flexibility of the matrix they can vibrate freely in lateral direction and, second, due to shrinking to the nanoscale, predominant directions of the polarization form, such as vortex-or bubble-like domain patterns. Piezoresponse force microscopy was performed on patterned and non-patterned samples with and without a top electrode to check the local piezoresponse. Comparison of both samples revealed an increase in lateral piezoactivity for patterned samples while the out-of-plane piezoresponse remained constant.