Oxide Ionic Transport Features in Gd-Doped La Nickelates
Full article
| Общее |
Language:
Английский,
Genre:
Full article,
Status:
Published,
Source type:
Original
|
| Journal |
Solid State Ionics
ISSN: 0167-2738
|
| Output data |
Year: 2020,
Volume: 357,
Article number
: 115462,
Pages count
: 8
DOI:
10.1016/j.ssi.2020.115462
|
| Tags |
Ruddlesden – Popper phases; Oxygen isotope exchange; Mass relaxation; Structure evolution; Oxygen mobility and surface reactivity; Chemical diffusion |
| Authors |
Sadykov Vladislav A.
1,2
,
Sadovskaya Ekaterina M.
1,2
,
Filonova Elena A.
3
,
Eremeev Nikita F.
1
,
Belyaev Vladimir D.
1
,
Tsvinkinberg Viktor A.
3,4
,
Pikalova Elena Yu.
3,4
|
| Affiliations |
| 1 |
Federal Research Center Boreskov Institute of Catalysis, Akad. Lavrentieva ave. 5, 630090 Novosibirsk, Russia
|
| 2 |
Novosibirsk State University, Pirogova str. 2, 630090 Novosibirsk, Russia
|
| 3 |
Ural Federal University named after the First President of Russia B.N. Yeltsin, Mira str. 19, 620002 Yekaterinburg, Russia
|
| 4 |
Institute of High Temperature Electrochemistry, UB RAS, Akademicheskaya str. 20, 620137 Yekaterinburg, Russia
|
|
Funding (2)
|
1
|
Russian Science Foundation
|
16-13-00112
|
|
2
|
Russian Foundation for Basic Research
|
20-03-00151 (АААА-А20-120022090045-9)
|
In this work new RP materials of the La2-xGdxNiO4+δ series were synthesized and their structural features, oxygen stoichiometry and transport properties were studied by X-ray diffraction, TGA, mass relaxation method and oxygen isotope exchange with C18O2 in a flow reactor. According to XRD data, La2-xGdxNiO4+δ (x = 0.0; 0.2; 0.4) are single-phase samples with a tetragonal structure. Doping with Gd resulted only in the insignificant increase of the interstitial oxygen content (δ changes in the range of 0.13–0.15). A high oxygen mobility was demonstrated: at 700 °C
Dchem ~ 10−5 cm2/s (mass relaxation data) and self–diffusion coefficient D* ~ 10−8 cm2/s (oxygen isotope exchange data). Such characteristics are determined by the cooperative mechanism of oxygen migration involving both regular and highly-mobile interstitial oxygen. Gd doping, however, resulted in non-uniformity of the oxygen migration routes. To describe this feature, a mathematical model has been developed including a slow exchange between neighboring oxide anions. Oxygen mobility decreases with increasing Gd content.