Kraftmikroskopische Untersuchungen dünner ferroelektrischer Filme

This thesis reports the inspection and manipulation of thin ferroelectric films of lead titanate (PbTiO3 : PTO), lead zirconium titanate (Pb(Zr0.25Ti0.75)O3 : PZT), and barium titanate (BaTiO3 : BTO) by means of scanning force microscopy - specifically Piezoresponse and Kelvin-Probe. The film thickness of the investigated samples ranged between 50nm and 800nm. This experimental work focussed on the following issues: native domain structures, creation of domains by short voltage pulses and area-switching with the force microscope, local qualitative and quantitative measurements of the ferroelectric hysteresis loops, and investigations at the interface between film and platinum-electrode in the PZT/Pt-System. Lamellar domain structures were visualized with high lateral resolution of 5nm on the surface of the PTO-samples, whereas the PZT- and BTO-samples showed prepolarisation and no domains. In the switching experiments a pronounced thickness dependence was found and partly a good agreement to macroscopic measurements. For BTO-films of 50nm and 125nm thickness no stable switching of polarisation could be observed. Using appropriate preparation methods it was possible to provide evidence of a 200nm thick interface layer with reduced polarisation above the electrode in the PZT/Pt-system.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Technische Universität Dresden

Year

2004

Author dc:creator

• Schlaphof, Frank

Contributors dc:contributor

• Eng, Lukas
• Waser, Rainer
• Gerlach, Gerald

• Domänen
• Ferroelektrika
• Hysteresen
• Kelvin Sonde
• Kraftmikroskopie
• Piezoresponse
• dünne Schichten
• Ferroelectrics
• domains
• force microscopy
• hysteresis loops
• kelvin probe
• thin films