Synthesis and crystal structure determination of YCo1−x Fe x O3 (x = 0, 0.33, 0.5, 0.67 and 1) perovskites

Abstract

The results on synthesis, crystal structure determination and calculation of crystallochemical parameters of YCo1−x Fe x O3 (x = 0, 0.33, 0.5, 0.67 and 1) perovskites are presented in this work. The compounds within this series were synthesized by solution combustion method using two different fuels: urea and citric acid. It was found that iron-containing perovskites, obtained by citric acid as a fuel are of better quality and crystallinity. All the compounds crystallize in Pnma space group with Z= 4. According to the structure and the calculated crystallochemical parameters, the coordination number of Y3+ in these perovskites is 8. The unit cell parameter relationship is of O−type suggesting that the main reason for distortion of ideal perovskite structure is the octahedral tilting. The deformation of the octahedrons, as well as the tilting angles, are increasing with the increasing content of Fe3+ but the calculated global instability indices (GII) show that the stability of the perovskite structure is increasing with increasing of the Fe3+ content. The perovskites YCo1−x Fe x O3 (0 ≤ x ≤ 1) obtained by solution combustion method are isomorphous and crystallize in Pnma space group. The main reason for deviation from the ideal perovskite structure is tilting of the octahedra. The substitution of Co3+ with Fe3+ leads to a more distorted and tilted octahedron.