Study of structural, microstructure, impedance, and DC conductivity of Gd-doped SrCeO3 ceramics

• Published in: Applied physics. A, Materials science & processing Vol. 127; no. 12
• Main Authors: Yadav, Dharmendra, Nirala, Gurudeo, Yadav, Sushma, Kumar, Upendra, Upadhyay, Shail, Kumar, Satyam
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2021; Springer Nature B.V
• Subjects: Applied physics; Cerium; Characterization and Evaluation of Materials; Condensed Matter Physics; Conductors; Crystallization; Crystals; Gadolinium; Grain size; Impedance; Lattice vacancies; Machines; Manufacturing; Materials science; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; Raman spectroscopy; Spectrum analysis; Strontium carbonate; Surfaces and Interfaces; Thin Films; X ray photoelectron spectroscopy; SrCeO; Raman; XPS; Rietveld refinement; Electrical conductivity
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-021-05112-5

Samples of the system SrCe 1−x Gd x O 3 (x = 0.0, 0.02, 0.04, 0.06 and 0.10) were prepared using a conventional ceramic route. The phase and structural properties of samples were investigated using X-ray diffraction. Rietveld refinement of the XRD data supported the crystallization of samples in an orthorhombic structure under space group Pnma . FTIR and TGA measurements indicated the presence of SrCO 3 in all the samples. The incorporation of Gd into the lattice was shown to reduce the direct optical bandgap and average grain size. The DC conductivity of the cylindrical pellets of samples was investigated using AC impedance measurements at temperatures ranging from 300 to 600 °C. The highest conductivity was observed for the composition SrCe 0.98 Gd 0.02 O 3 such as 1.54 × 10 −3  Scm −1 at 600 °C. This compound has the potential to be work as mixed ionic and electronic conductor for SOFCs. The XPS spectra of Ce 3d and O 1 s confirmed the presence of Ce in both Ce 3+ and Ce 4+ states and oxygen vacancies. The oxygen vacancies in the samples were analyzed using Raman spectroscopy.