Synthesis, structure, oxygen stoichiometry, and electrical properties of doped ruddlesden-popper strontium cobaltite Sr1·875Ce0·025CoO4-δ, Sr1·875Ce0·025Co0·75Ni0·25O4+δ novel compounds

Abstract

We report the synthesis of Sr1·875Ce0·025CoO4-δ and Sr1·875Ce0·025Co0·75Ni0·25O4+δ for the first time, each compound was synthesised using Co-precipitation and Sol-Gel methods, at 1050 °C for 144 and 120 h respectively. Oxygen stoichiometry was determined using Iodometric titration, we have noticed oxygen hypostoichiometry for Ce-doped compound and hyperstoichiometry state after Ni-doping. Electrical properties were studied for sintered pellets, Electrical resistance was measured in the range (−0.5–+0.5 v). Specific electrical resistivity and electrical conductivity were calculated from resistance measurements. It was found that the Ce-doped compound has about three times higher conductivity (σC1 = 0.000000058423295 s cm−1) Compared with the Ni-doped one (σN2 = 0.000000022384787 s cm−1). Electrical Capacitance was measured at 1 kHz frequency, the relative dielectric constant εr, and the loss tangent tanδ were calculated accordingly. The results showed that the Ni-doped compound has higher capacitance but lower εr and dissipation factor values.

Keywords

• Ruddlesden-popper
• RP
• Co-precipitation
• Sol-gel
• XRD
• Iodometry