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1071-F01-07

Concentric Metallic-Piezoelectric Microtube Arrays H.J. Fan1, S. Kawasaki1, J. M. Gregg2, A. Langner3, T. Leedham4, and J. F. Scott1 1 Department of Earth Sciences, University of Cambridge, Cambridge, CB2 3EQ, United Kingdom 2 Centre for Nanostructured Media, Queen's University of Belfast, Belfast, BT7 1NN, United Kingdom 3 Max Planck Institute of Microstructure Physics, Halle, 06120, Germany 4 Multivalent Ltd., The Laboratory, Eriswell, IP27 9BJ, United Kingdom ABSTRACT Trilayer concentric metallic-piezoelectric-metallic microtubes are fabricated by infiltrating porous Si templates with sol precursors. LaNiO3 (LNO) is used as the inner and outer electrode material and PbZrTiO3 (PZT) is the middle piezoelectric layer. Structure of the microtubes is characterized in details using scanning and transmission electron microscopy which are equipped with energy dispersive x-ray spectroscopy for elemental mapping. The hysteresis of a trilayer thin film structure of Pt-PZT-LNO is shown. These trilayer microtubes might find applications in inkjet printing.

INTRODUCTION The infiltration technique utilizing porous templates appears to be a generic method for fabrication of nano and microtubes of a large variety of materials including metals and dielectric oxides (1,2) and metals (3,4). A number of reports have been made on fabrication of ferroelectric/piezoelectric nano- and microtubes through infiltration of trenched templates (3-8). Other techniques have also merged, e.g., Pb(ZrxTi1-x)O3 (PZT) and BaTiO3 nanotubes by physical coating of vertical nanowires (9) and carbon nanotubes (10), quartz tubes by Licatalyzed oxidation of porous Si (11), PbTiO3 microtubes by chemical reaction of pre-grown TiO2 nanotubes with PbO vapor (12). For the application as piezoelectricity-based nanofluidic channels (e.g., liquid spray), a ferroelectric tube with a tube diameter in the micrometer range is more suitable than nanotubes. For example, the nozzle size of an inkjet printer head or a liquid drug sprayer is tens of micrometers, therefore, arrays of the piezotubes with an inner tube diameter of 1-10 micron are needed. In this content, the infiltration technique is a simple and cheap method compared to MOCVD (13), sputtering, and atomic layer deposition. An array of electrode-piezoelectricelectrode concentric tubes should be possible by multiple infiltration of the porous template. Bharadwaja et al.(8) conducted a systematic synthesis and structural characterization work on PZT microtubes sandwiched by LaNiO3 and Pd concentric layers. They applied a vacuumassisted infiltration which appears to be advantageous over the ambient-pressure infiltration and showed a linear increase of the tube wall thickness with increasing the number of infiltrations. The property characterization was made either azimuthally by scanning a conductive AFM tip over the surface of the tubes which lie horizontally on a platinized substrate (9), or longitudinally from two ends of the tubes (6). No work has been done so far to measure the

radial ferro/pi