Equilibrium of intrinsic and impurity point defects in Ca-doped Sm2Zr2O7

In this work, a doping strategy was used to achieve a good conductivity in samarium zirconate which crystallizes in the pyrochlore.The production of nanopowders made it possible to form high-density ceramics with an optimal microstructure.It is shown that intrinsic and impurity defects coexist in Sm 2-x Ca x Zr 2 O 7-δ , impairing ion transport at high doping levels.Despite this, Sm 1.95 Ca 0.05 Zr 2 O 7-δ maintains low activation energy of the parent and has good ionic conductivity (10 -3 S•cm -1 at 600 • C) which is one of the largest among oxide pyrochlores.It has been shown to have a good chemical stability.The material has a thermal expansion coefficient (TEC) of 12 ppm K -1 which is higher than YSZ and provides better compatibility with electrode materials.The above makes it possible to successfully use it as a highly stable oxygen electrolyte or an intermediate thin layer at the electrolyte-electrode interface in electrochemical devices.