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CPP: Chemische Physik und Polymerphysik

CPP 18: Physics of polymers II

CPP 18.2: Vortrag

Dienstag, 8. März 2005, 11:30–11:45, TU C130

Study on the Ferroelectric Properties of Poly (vinylidene fluoride-trifluoroethylene) P(VDF/TrFE) Copolymer Nanotubes — •Yun Luo¹, Markus Geuss², Petra Göring¹, Klaus Rademann², Martin Steinhart¹, and Ulrich Gösele¹ — ¹Max-Planck-Institute of Microstructure Physics, Halle/S, Germany — ²Institute of Chemistry, Humboldt University of Berlin, Berlin, Germany

Nanotubes and nanowires consisting of P(VDF/TrFE) copolymers with diameters from 25 nm to 400 nm have been fabricated via wetting of porous alumina templates and a subsequent annealing step under argon. By selectively removing the template, released tubes or rods with smooth walls and high aspect ratio were obtained. Large scale free-standing P(VDF/TrFE) nanotubes can also be obtained, with their open end connected to a P(VDF/TrFE) membrane and the capped end upward.

XRD measurements were performed on copolymer nanotube and nanowire arrays still embedded within the templates and revealed that the nano-objects were crystalline and exhibited a texture.

In order to demonstrate local ferroelectric behaviour, individual P(VDF/TrFE) tubes were characterized by AFM imaging and PFM performed in contact mode with a conductive cantilever (force constant   0.25 N/m). Local (remnant) piezoelectric hysteresis loops were measured by successive application of rectangular voltage pulses. Sub-micrometer domains along the tube length axis can be well resolved in the PFM image in which hysteresis loops are recorded.