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The Sm2MoO6 compounds, also known as oxymolybdates, were synthesized in air using a solid-phase method. A series of techniques were employed to characterize the undoped and, for the first time, lead-doped samples. It has been demonstrated that lead-containing samples form a wide range of solid solutions, which are isostructural (sp. gr. C2/c) to the pure monoclinic Sm2MoO6 compound. The thermal stability, polymorphism, and conductive properties of the obtained samples were studied in detail. Doping Sm2MoO6 ceramics with lead results in a notable increase in conductivity compared to the pure sample, with conductivity reaching 10−3 S cm−1 at 900 °C. This improvement is due to the formation of oxygen vacancies through the heterovalent substitution of cation sublattice. In contrast to undoped samarium oxymolybdates, Pb-containing Sm2MoO6 ceramics demonstrate the capacity to transfer protons, resulting in an overall increase in conductivity in a wet environment. [ABSTRACT FROM AUTHOR]

The conductive properties of fluorite-like structures KLn4Mo3O15F (Ln = La, Pr, Nd: KLM, KPM, KNM) have been studied theoretically and experimentally. Theoretical studies included the geometrical-topological analysis of voids and channels available for migration of working ions; bond valence site energy calculations of the oxygen ions' migration energy; quantum-chemical calculations for the estimation of the oxygen vacancies formation energy. Experimental measurements of conductivity were made using impedance spectroscopy and as a function of oxygen partial pressure. The total conductivity was ∼10−3 S cm−1 for KLM and ∼10−2 S cm−1 for KPM and KNM at 800 °C. Measurements with changes in partial pressure proved the mixed nature of electric transport in KLM, KPM, and KNM phases, with predominantly ionic conductivity. The measured ion transference numbers in air reached approximately 0.9 at 800 °C for the KPM and KNM ceramics. Also, evaluated proton transfer numbers were less than 10%, indicating a small contribution to the total conductivity. [ABSTRACT FROM AUTHOR]

The conductive properties of fluorite-like structures KLn 4 Mo 3 O 15 F (Ln = La, Pr, Nd: KLM, KPM, KNM) have been studied theoretically and experimentally. Theoretical studies included the geometrical-topological analysis of voids and channels available for migration of working ions; bond valence site energy calculations of the oxygen ions' migration energy; quantum-chemical calculations for the estimation of the oxygen vacancies formation energy. Experimental measurements of conductivity were made using impedance spectroscopy and as a function of oxygen partial pressure. The total conductivity was ∼10 -3 S cm -1 for KLM and ∼10 -2 S cm -1 for KPM and KNM at 800 °C. Measurements with changes in partial pressure proved the mixed nature of electric transport in KLM, KPM, and KNM phases, with predominantly ionic conductivity. The measured ion transference numbers in air reached approximately 0.9 at 800 °C for the KPM and KNM ceramics. Also, evaluated proton transfer numbers were less than 10%, indicating a small contribution to the total conductivity.