Regensburg 2004 – wissenschaftliches Programm
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DF: Dielektrische Festkörper
DF 2: Elektrische und optische Eigenschaften II
DF 2.6: Vortrag
Montag, 8. März 2004, 16:30–16:50, H11
Time domain electric field relaxation, accessing the low temperature dependence of the ionic conductivity in Li3xLa2/3−xTiO3 — •Alberto Rivera1,2, Jacobo Santamaria1, Carlos Leon1, Thomas Blochowicz2, Catalin Gainaru2, and Ernst Roessler2 — 1GFMC, Dpto. Fisica Aplicada III, Universidad Complutense de Madrid, 28040 Madrid, Spain — 2Experimentalphysik II, Universität Bayreuth, 95440 Bayreuth, Germany
The measurements of the modulus in the time domain, that is the relaxation of the electric field at constant dielectric displacement D, presents several advantages over the more spread permittivity technique. In particular, the electric response of ionic conductors can only be probed in the time domain by a modulus experiment. We analyze the dynamics of a fast ionic conductor, namely crystalline Li0.18La0.61TiO3.
We introduce a capacity correction algorithm to obtain the spectra of the electric response from time domain measurements allowing a standard data analysis in the frequency domain. In this way ionic dynamics are investigated in the frequency range 10−5 − 102 Hz and for conductivity values in the range 10−14 − 10−8 S/cm. The DC ionic conductivity shows an Arrhenius temperature dependence below 300 K and down to 120 K, in contrast to the non-Arrhenius behavior found at higher temperatures, making it impossible to apply the Vogel-Fulcher-Tammann law.