Title: DIELECTRIC RELAXATION IN NaNbO_3 SINGLE CRYSTAL
Author(s): K.Konieczny (Institute of Physics and Computer Science, Pedagogical University, 2 Podchorazych Str., 30-084 Krakow, Poland)

Dielectric permittivity studies of reduced samples of NaNbO$_3$ single crystal in the range of temperatures 30-500 $^{\circ}$C and frequency 20 Hz-1 MHz are reported. In this temperature range a relaxation process is observed in the frequency range of about 100 kHz. This is an additional process to the earlier reported one [7]. The obtained data were fitted to Cole-Cole formula. The dispersion step $\Delta\epsilon$ (the maximum value of $\Delta\epsilon$ =1000) is temperature dependent. The mean relaxation time $\tau$ does not obey the Arrhenius law above T$_{\rm C}$. The occurrence of this relaxation process may be connected with oxygen vacancies.

Comments: Figs. 4, Refs. 8, Tabs. 0.