TY  - JOUR
AU  - Ceretti, Monica
AU  - Wahyudi, Olivia
AU  - André, Gilles
AU  - Meven, Martin
AU  - Villesuzanne, Antoine
AU  - Paulus, Werner
TI  - (Nd/Pr) 2 NiO 4+δ : Reaction Intermediates and Redox Behavior Explored by in Situ Neutron Powder Diffraction during Electrochemical Oxygen Intercalation
JO  - Inorganic chemistry
VL  - 57
IS  - 8
SN  - 1520-510X
CY  - Washington, DC
PB  - American Chemical Society
M1  - FZJ-2019-00342
SP  - 4657 - 4666
PY  - 2018
AB  - Oxygen intercalation/deintercalation in Pr2NiO4+δ and Nd2NiO4+δ was followed by in situ by neutron powder diffraction during the electrochemical oxidation/reduction reaction, in a dedicated reaction cell at room temperature. Three phases were identified for both systems: orthorhombic RE2NiO4.23, obtained by classical solid-state reaction, gets reduced in a 2-phase reaction step to a tetragonal intermediate phase RE2NiO4+δ with 0.07 ≤ δ ≤ 0.10, which again transforms on further reduction in a 2-phase reaction step towards the stoichiometric RE2NiO4.0. Electrochemical oxidation does not proceed fully reversibly for both cases: while the re-oxidation of Nd2NiO4+δ is limited to the tetragonal intermediate phase with δ = 0.10, the homologous Pr2NiO4+δ can be re-oxidized up to δ = 0.17, showing orthorhombic symmetry. For the tetragonal Pr2NiO4.12 phase, we were able to establish a complex anharmonic displacement behavior as analyzed by single crystal neutron diffraction and Maximum Entropy Analysis, in agreement with a low-T diffusion pathway for oxygen ions activated by lattice dynamics.
LB  - PUB:(DE-HGF)16
C6  - pmid:29620364
UR  - <Go to ISI:>//WOS:000430437400050
DO  - DOI:10.1021/acs.inorgchem.8b00393
UR  - https://juser.fz-juelich.de/record/859489
ER  -