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D2.9.1

FTIR Characterization Of PZT Nano Fibers Synthesized from Metallo-organic Compounds Using Electrospinning

Yu Wang and Jorge J. Santiago-Avilés Department of Electrical and System Engineering, University of Pennsylvania, Philadelphia, PA 19104 ABSTRACT We have synthesized Pb(Zr0.54Ti0.48)O3 fibers with diameter ranging from 500 nm to several microns using electrospinning and metallo-organics decomposition (MOD) techniques. By a refinement of our electrospinning technique, i.e. by increasing the viscosity of the precursor solution, and by adding a filter to the tip of the syringe, the diameter of synthesized PZT fibers has been reduced to the neighborhood of a hundred nanometers. The complex thermal decomposition was characterized using Fourier-transform infrared (FTIR) spectroscopy and xray diffraction (XRD). It was found that alcohol evaporated during electrospinning and that the organic groups had pyrolized before the intermediate pyrochlore phase was formed. There is a good correspondence between XRD and FTIR spectra. It was also found that a thin film of platinum coated on silicon substrate surface not only seems to have catalyzed the phase transformation to PZT but also favored the formation of 110 texture in the synthesized PZT fibers. INTRODUCTION One-dimensional (1D) nanostructures, such as nanowires, or nanofibers, nanotubes and molecular wires, are the smallest dimension structures for efficient transport of electrons and optical excitations. They can be used as building blocks in bottom-up assembly in diverse applications in nano-electronics and photonics. These buildings could overcome fundamental limitations of conventional microfabrications based on lithography [1, 2]. Lead zirconate titanate, Pb(ZrxTi1-x)O3 (PZT) is well known for its technological importance in the field of sensors, electronics and non-volatile ferroelectric memory devices. PZT nanofibers are expected to find wide applications in nano-electronics, photonics and sensors [3, 4]. However, in contrast to the multiplicity of synthesis methods used for powders and thin films, only a few ways have been found for PZT fibers, all with diameter larger than 10µm [5-9]. The authors synthesized PZT fibers with diameter from 500nm to 10µm using electrospinning and metallo-organics decomposition (MOD) techniques [10]. Such a diameter range is not small enough for nano-scale applications. Fortunately, we have recently refined PZT fibers by improvement on our synthesis techniques. On the other hand, since many organic and metal-oxygen bonds are infrared active, Fourier-transform infrared (FTIR) spectroscopy may be an effective way to characterize the thermal decomposition of metallo-organics. In fact, FTIR has been used to investigate hydrolysis of metallo-organic solution during sol-gel synthesis of PZT thin film or powder [11-15]. So far FTIR has not been commonly used to characterize MOD process. This paper will report our efforts to do so, as well as our efforts to refine the fibers dimensions and morphology.

D2.9.2

EXPERIMENT The star