Structure, nonstoichiometry and thermal expansion of the NdBa(Co,Fe)2O5+δ layered perovskite
Abstract NdBaCo 2− x Fe x O 5+δ (0.0 ≤  x  ≤ 2.0) series were prepared by a solid state reaction. Singe phase solid solutions were obtained within the range 0.0 ≤  x  ≤ 1.4. The crystal structure of iron substituted solid solutions NdBaCo 2− x Fe x O 5 + δ was described within the tetragonal unit cell a p × a p × 2a p (S.G. P4/mmm ). The substitution of cobalt for iron leads to the monotonous increase of the unit cell parameters and the unit cell volume. The values of the oxygen content in NdBaCo 2− x Fe x O 5 + δ ( x  = 0; 0.2) as a function of temperature were determined by TGA. The thermal expansion measurements of NdBaCo 2− x Fe x O 5 + δ ( x  = 0; 0.2; 0.4; 0.6 and 0.8) were performed. Chemical expansion constituent was separated.