D.S. Tsvetkov

Crystal structure and physicochemical properties of layered perovskite-like phases LnBaCo2O5 + δ

Complex oxides LnBaCo2O5 + δ (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y) were obtained by solid-state synthesis at 1373 K in air. The crystal structure of layered perovskites LnBaCo2O5 + δ was studied by X-ray and neutron diffraction analyses. It was shown that cobaltites LnBaCo2O5 + δ crystallized in tetragonal (space group P4/mmm, 0.6 > δ > 0.45) or orthorhombic (space group Pmmm, 0.6 > δ > 0.45) structures depending on the radius of the lanthanide ion and the oxygen content. The dependences of the unit cell parameters of LnBaCo2O5 + δ on the radius of the lanthanide ion were obtained. The average thermal expansion coefficients at temperatures from 298 to 1373 K in air were determined. The dependence of the chemical component of thermal expansion on the oxygen content was evaluated for LnBaCo2O5 + δ (Ln = Nd, Sm, Gd, Y).

The diffusion of oxygen and ion transport in lanthanum cobaltite LaCoO3-δ

AbstractThe chemical diffusion coefficient of oxygen vacancies and oxygen ion conductivity in lanthanum cobaltite LaCoO3 were determined by the polarization method as functions of oxygen partial pressure

The oxygen nonstoichiometry and defect structure of unsubstituted LaCoO3−δ cobaltite

p_{O_2 }

Oxygen nonstoichiometry, defect structure and defect-induced expansion of undoped perovskite LaMnO3±δ

(atm) and temperature T(K) over the ranges −4 ≤ log

Oxygen nonstoichiometry and defect structure of undoped and doped lanthanum cobaltites

p_{O_2 }

Defect structure and charge transfer in undoped and doped lanthanum cobaltites

≤ 0 and 1173 K ≤ T ≤ 1323 K. The mobilities (cm2/(V s)) of oxygen vacancies calculated over the temperature range studied satisfy the inequalities 1.8 × 10−5 ≤