Synthesis features and determination of oxygen content in double perovskite-like manganites LnBaMn2O6–δ (Ln = Nd, Sm)

LnBaMn2O6–δ (Ln = Nd, Sm) oxides were synthesized by the glycine–nitrate combustion method in 3 steps. The crystal structures of LnBaMn2O6–δ were found to possess a tetragonal cell with a space group of P4/mmm or P4/nmm for Ln = Nd or Sm, respectively. The oxygen content of LnBaMn2O6–δ determined iodometric titration methods was close to 6.0. TG measurements at a variable atmosphere (air or 5 % H2/Ar) were performed to simulate the single CLOU cycle. Both samples are demonstrated to weight loss down to 4.5 wt. % in 5% H2/Ar at 950 °C and reversible oxygen saturation in the air atmosphere at 400 °C was observed. The set of the observed characteristics of LnBaMn2O6–δ (Ln = Nd, Sm) distinguishes these materials as an effective oxygen carrier in a CLOU process.