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DF: Fachverband Dielektrische Festkörper

DF 16: Thin Films and Nanostructures III

DF 16.5: Vortrag

Donnerstag, 26. März 2009, 16:10–16:30, WIL B321

Nonlinear Frequency Response of Metal/Ferroelectric/Metal and Metal/Ferroelectric/Semiconductor Heterostructures — •Kay Barz, Martin Diestelhorst, and Horst Beige — Martin Luther-Universität Halle-Wittenberg

By investigating the dynamic behavior of a ferroelectric-semiconductor heterostructure we observed a torus doubling bifurcation together with other interesting frequency responses obviously driven by the nonlinear nature of the sample.[1] In the talk, some of these experimental findings will be presented, mainly focusing on the amplitude-frequency-characteristics observed at different structure types (metal/ferroelectric/metal (MFM) and metal/ferroelectric/semiconductor (MFS)). Concerning the MFS heterostructures it was to clarify, whether the observed nonlinear phenomena can be attributed to the ferroelectric thin film or the semiconductor substrate or if it is an emergent property (i.e. spontaneously arising owing to the system’s complexity). Therefore the behavior of the MFS structures was compared to simple MOS-capacitors (metal/oxide/semiconductor). The results on MFM structures show, how hysteresis and its transient alterations due to fatigue manifest in the frequency response. It turns out that ferroelectric thin films and ferroelectric/semiconductor heterostructures provide easy experimental access to interesting phenomena known from theory of nonlinear dynamics.

[1] M. Diestelhorst et.al.; Phil.Trans.Roy.Soc.A; 366; 437-446; 2008.