Electrical Conduction and Relaxation in Perovskite Oxide SrCe0.98Na0.02O3 Synthesized by Solid-State Route

Abstract

Powder of SrCe0.98Na0.02O3 is synthesized by calcination at 1000 °C for 8 h via solid-state ceramic route. The ceramic/pellet of this compound is obtained by sintering at 1200 °C for 12 h. X-ray diffraction (XRD) technique is used to confirm single-phase formation. Rietveld refinement of the XRD pattern of sintered powder has confirmed orthorhombic crystal structure and space group Pnma as reported for SrCeO3. Further, the purity of the synthesized compound is ensured using Raman and Fourier transform infrared spectroscopy analysis. Scanning electron microscopic studies have reflected dense microstructure and spherical shape grains with an average size of 1.80 µm. Complex plane impedance and spectroscopic analysis are employed to study electrical conduction and relaxation mechanisms in the temperature range 300–600 °C and frequency range 20 Hz to 2 MHz. The activation energy for DC conduction (Econ) and relaxation (Erelx) is found to be the same (0.77 eV). Based on the numerical value of activation energies, conduction and relaxation mechanisms are attributed to migration of doubly ionized oxygen vacancies (VO ••). © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim