When 3:30 PM - 4:30 PM Feb 24, 2006
Where 1504 Dow Conn.
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Influence of Local Thin Film Texture on Ferroelectric Hysteresis


John Blendell - Purdue University

Commercial ferroelectric thin film devices are rapidly approaching the same nanoscale dimensions as individual grains, yet little is known about the influence of grain boundaries and local texture on ferroelectric properties. Accordingly, several complementary experimental and theoretical techniques are being developed to assess the local ferroelectric response. Combining quantitative piezo-force microscopy (PFM), electron backscattering diffraction (EBSD), and two-dimensional object oriented finite element modeling (OOF), various individual crystallographic distributions with either beneficial or detrimental effects can be identified and eventually predicted.
Crystallographic orientation can now be determined with nanometer scale lateral resolution using electron backscattering diffraction (EBSD), allowing the orientation of individual ferroelectric grains to be mapped. Two-dimensional object oriented finite element modeling (OOF) has also recently advanced to allow prediction of the piezoresponse of a polycrystalline thin film with full consideration of the sample texture as determined by EBSD. Piezoelectric force microscopy (PFM) was employed to experimentally determine the ferroelectric properties of the same grain and grain boundary regions considered by EBSD and OOF. This AFM-based technique is widely used, but can be significantly hindered by several instrumental artifacts that were identified and overcome during this work. The area of piezoelectric hysteresis loops determined correlate with the predictions using OOF and the texture measured by EBSD.