| Summary: | Perovskite anodes, nowadays, are used in any solid oxide fuel cell (SOFC) instead of conventional nickel/yttria-stabilized zirconia (Ni/YSZ) anodes due to their better redox and electrochemical stability. A few compositions of samarium-substituted strontium titanate perovskite, Sm<sub>x</sub>Sr<sub>1−x</sub>TiO<sub>3−δ</sub> (x = 0.00, 0.05, 0.10, 0.15, and 0.20), were synthesized via the citrate-nitrate auto-combustion route. The XRD patterns of these compositions confirm that the solid solubility limit of Sm in SrTiO<sub>3</sub> is x < 0.15. The X-ray Rietveld refinement for all samples indicated the perovskite cubic structure with a <inline-formula> <math display="inline"> <semantics> <mrow> <mi>P</mi> <mi>m</mi> <mover accent="true"> <mn>3</mn> <mo>¯</mo> </mover> <mi>m</mi> </mrow> </semantics> </math> </inline-formula> space group at room temperature. The EDX mapping of the field emission scanning electron microscope (FESEM) micrographs of all compositions depicted a lower oxygen content in the specimens respect to the nominal value. This lower oxygen content in the samples were also confirmed via XPS study. The grain sizes of Sm<sub>x</sub>Sr<sub>1−x</sub>TiO<sub>3</sub> samples were found to increase up to x = 0.10 and it decreases for the composition with x > 0.10. The AC conductivity spectra were fitted by Jonscher’s power law in the temperature range of 500−700 °C and scaled with the help of the Ghosh and Summerfield scaling model taking <i>ν<sub>H</sub></i> and <i>σ<sub>dc</sub> T</i> as the scaling parameters. The scaling behaviour of the samples showed that the conduction mechanism depends on temperature at higher frequencies. Further, a study of the conduction mechanism unveiled that small polaron hopping occurred with the formation of electrons. The electrical conductivity, in the H<sub>2</sub> atmosphere, of the Sm<sub>0.10</sub>Sr<sub>0.90</sub>TiO<sub>3</sub> sample was found to be 2.7 × 10<sup>−1</sup> S∙cm<sup>−1</sup> at 650 °C, which is the highest among the other compositions. Hence, the composition Sm<sub>0.10</sub>Sr<sub>0.90</sub>TiO<sub>3</sub> can be considered as a promising material for the application as the anode in SOFCs.
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