Partner und Internationale Organisationen
(Englisch)
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AT, BE, CZ, DK, FR, DE, IE, IT, LV, LT, NO, PL, PT, RO, SI, ES, SE, CH, TR, UK
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Abstract
(Englisch)
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Ferroelectric -relaxor ceramics exhibit excellent dielectric and piezoelectric properties. The present project centered on the fabrication and characterization of ferrlelectric thin films, with the aim of identifying and understanding the differences and similitude between thin films and bulk ferroelectric-relaxor materials. Ordered and Disordered Lead Scandium Tantalum (PST) thin films were made by a sol-gel technique. Thin films samples on a variety of substrates systems showed an increase in the dielectric constant upon the increase of their positional order, in contrast to bulk ceramics. Highly ordered thin films showed the development of a ferroelectric state and dielectric properties comparable to their bulk counterparts. Disordered PST films displayed the essential features of relaxor behavior including frequency dependence of the dielectric maximum, however the dielectric response was greatly reduced as compared to ceramics - this is likely to be a result of increased density of defects in the films. In addition we elaborated ordered and disordered bulk ceramics, lead magnesium tantalate, and evaluated their dielectric properties under electric field and pressure.The films and the ceramics were studied by means of high resolution electron microscopy, electrical characterisation technique at a wide frequency range and IR spectroscopy. Collaborating partners included Frech groups, a Czech group as well as collaborations with American and Korean groups.
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