Berlin 2005 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

DF: Dielektrische Festkörper

DF 4: Poster

DF 4.21: Poster

Samstag, 5. März 2005, 08:30–16:30, Poster TU C

DIELECTRIC RELAXATION IN STRONTIUM TITANATE CONTAINING A- AND B- SUBSTITUTIONS — •Andrey Sotnikov^1,2, Elena Smirnova², Wolfgang Häßler¹, Manfred Weihnacht¹, and Vladislav V. Lemanov² — ¹Leibniz Institute for Solid State and Materials Research Dresden, Dresden, Germany — ²A.F.Ioffe Physical-Technical Institute, St. Petersburg, Russia

Over the many years a number of ferroelectrics and high permittivity systems closely related to ferroelectrics showing a strong dielectric relaxation, have been studied. Some of them were solid solutions based on SrTiO3 and KTaO3 incipient ferroelectrics. In the present work, we studied systematically the effect of A-, B- and complex A- and B- simultaneous substitution in SrTiO3 on dielectric relaxation processes. For this purpose ceramic samples of strontium titanate containing Pb(2+), Ba(2+), Zr(4+), and Pb(2+)Zr(4+) were prepared. Dielectric spectra were measured between 0.1 Hz and 1 MHz in a wide temperature range from 4.2 K to 400 K. A well-developed dielectric relaxation of different types (from simple Debye-type to relaxor-type with broad distribution of relaxation times) were observed. The main features and possible mechanisms of the relaxation are discussed.