Influence of annealing at intermediate temperature on oxygen transport kinetics of Pr2NiO4+d

Saim Saher (1) , Jia Song (1) , Vaibhav Vibhu (2) , Clément Nicollet (2) , Aurelien Flura (2) , Jean-Marc. Bassat (2) , Henny J. M. Bouwmeester (1)

1 MESA+ - Institute for Nanotechnology
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Electrical conductivity relaxation (ECR) and oxygen permeation measurements were conducted, at 750 °C, to assess the long-term oxygen transport characteristics of the mixed ionic–electronic conducting Pr2NiO4+δ with a K2NiF4 structure. The results show that the apparent values for the oxygen diffusion and surface exchange coefficients extracted from the data and the associated oxygen flux increase over 120 h by 1–2 orders of magnitude. The results of post-mortem X-ray diffraction analysis of the samples show partial to virtually complete decomposition of Pr2NiO4+δ under the conditions of the experiments to Pr4Ni3O10+δ, PrNiO3−δ, Pr6O11, and traces of NiO. Pulse 18O–16O isotopic exchange (PIE) measurements confirmed fast surface exchange kinetics of the higher-order Ruddlesden–Popper phase Pr4Ni3O10+δ and Pr6O11 formed upon decomposition. Additional factors related to the microstructure, however, need to be considered to explain the observations.

Domaines: Matériaux

Saim Saher, Jia Song, Vaibhav Vibhu, Clément Nicollet, Aurelien Flura, et al.. Influence of annealing at intermediate temperature on oxygen transport kinetics of Pr2NiO4+d. Journal of Materials Chemistry A, 2018, 6 (18), pp.8331-8339. ⟨10.1039/c7ta08885j⟩. ⟨hal-01794207⟩