Dresden 2011 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

DF: Fachverband Dielektrische Festkörper

DF 12: Poster

DF 12.11: Poster

Mittwoch, 16. März 2011, 15:00–17:30, P1

Temperature dependence of x-ray diffuse scattering near T^⋆ for Pb_0.78Ba_0.22Sc_0.5Ta_0.5O₃ relaxor. — •Tim Prüßmann¹, Bernd J. Maier¹, Boriana Mihailova¹, Carsten Paulmann¹, Marin Gospodinov², and Ulrich Bismayer¹ — ¹Mineralogisch-Petrographisches Institut, Universität Hamburg, Germany — ²Institute of Solid State Physics, Bulgarian Academy of Sciences, Sofia, Bulgaria

Synchroton single-crystal x-ray diffraction was applied to the canonical relaxor Pb_0.78Ba_0.22Sc_0.5Ta_0.5O₃ (PBST) to study the development of polar nanoregions. The temperature evolution of x-ray diffuse scattering (XDS) along ⟨110⟩^⋆ was followed by the ratio of the intensity of the XDS I_diff to the intensity of the corresponding Bragg peak I_Bragg. By using I_diff/I_Bragg the thermodynamical character of the phase transformation near the intermediate temperature T^⋆ associated with coupling of polar nanoregions was analysed. It is shown that the transformation process near T^⋆ is not of second-order and is most likely of tricritical character.