Structural, optical and electrical properties of M 0.025 Sm 0.175 Ce 0.8 O 2- δ : an electrolyte for IT-SOFCs

The system of compositions MySmx-yCe1-xO2-δ (M = Al, Ca, Mg & Sr, x = 0.20; y = 0.025) are investigated in the present study as electrolytes for IT-SOFCs. These samples are prepared by a low-temperature sol-gel process modified by sucrose-pectin to obtain a nanocrystalline powder. The synthesized nanocrystalline powder calcined at 600°C. The average crystallite size is in the range of 11–16 nm. The co-dopants Al, Ca, Mg & Sr promote densification of the SDC 20 at relatively lower sintering temperatures (<1300°C). These samples are characterized by XRD, Williamson-Hall plots, UV-Visible, Raman, FESEM, and impedance spectroscopy. The electrical conductivity is measured in the temperature range of 300–700°C. The sample with composition Sr0.025Sm0.175Ce0.80O2-δ (SrSDC) exhibits higher electrical conductivity of 0.03342 S/cm at 700°C. Hence, SrSDC can be used as an electrolyte for IT-SOFC applications.