Ion Mobility

The project aims at studying the impact of lattice dynamics and oxygen ordering on the amplification of oxygen mobility at low temperature in the non stochiometric K₂NiF₄-type Ruddlesden-Popper phases. In particular, it will allow evaluating and extending a newly proposed phonon-assisted oxygen diffusion mechanism, enabling to rationalize oxygen mobility features in solid oxides, from room to moderate temperatures.

If it can be confirmed that, at low temperature, oxygen mobility is essentially triggered by lattice instabilities combined with low energy phonon modes, this will have an important impact not only for a fundamental understanding of the diffusion mechanism, but also for the concept of designing and optimizing new oxygen ion conductors. It is obvious that this will strongly enhance their potential for a variety of technological applications such as oxygen membranes, sensors or catalysts, especially in the low temperature regime.

The proposed LTT crystal structure of Nd₂NiO_4.1 at room temperature, (a) the tetragonal unit cell consists of interpenetrating NdNiO₃ and Nd₂O₂ layers along the c-axis, (b) two different tetrahedral sites with Wyckoff symmetry 4b and 4e. Excess oxygen atoms selectively occupy only the 4b Wyckoff sites as observed with powder and single crystal neutron diffraction studies [Maity et al., Phys. Rev. Mat. (2021)].

Team:

Dr. Martin Meven (Instrument Supervisor HEiDi@MLZ, DFG project manager)

Team from other institutions:

Dr. Monica Ceretti (Institut Charles Gerhardt Montpellier (ICGM), Université Montpellier, ANR project manager)

Prof. Dr. Werner Paulus (ICGM, Université Montpellier)

N. N. (PhD, ICGM, Université Montpellier)

N. Viela (Technician, ICGM, Université Montpellier)

Dr. Antoine Villezusanne (Scientist, Bordeaux Institute of Condensed Matter Chemistry (ICMCB), CNRS)

Publications:

Infrared furnace for in situ neutron single crystal diffraction studies in controlled gas atmospheres at high temperatures; Fernando Magro, Monica Ceretti*, Martin Meven and Werner Paulus; Journal of Applied Crystallography 2021, article IN5048

Interdependent scaling of long-range oxygen and magnetic ordering in nonstoichiometric Nd₂NiO_4.10; Sumit Ranjan Maity, Monica Ceretti, Lukas Keller, Juerg Schefer, Martin Meven, Ekaterina Pomjakushina and Werner Paulus; Physical Review Materials 2021, 5, 14401

Long-range oxygen ordering linked to topotactic oxygen release in Pr₂NiO4+δ fuel cell cathode material; Rajesh Dutta, Avishek Maity, Anna Marsicano, Monica Ceretti, Dmitry Chernyshov, Alexei Bosak, Antoine Villesuzanne, Georg Roth, Giuditta Perversi and Werner Paulus; J. Mater. Chem. A 2020, 8, 13987-13995

Local Structures of Oxygen-Deficient Perovskite Sr₂ScGaO₅ Polymorphs Explored by Total Neutron Scattering and EXAFS Spectroscopy; Monica Ceretti, Giovanni Agostini, Michela Brunelli, Serena Corallini, Giuditta Perversi, Gabriel Cuello, Anna Marsicano and Werner Paulus; Inorg. Chem. 2020, 59, 9434-9442

Stripe Discommensuration and Spin Dynamics of Half-Doped Pr₃/2Sr₁/2NiO₄; Avishek Maity, Rajesh Dutta and Werner Paulus; Phys. Rev. Lett. 2020, 124, 147202

Structural disorder and magnetic correlations driven by oxygen doping in Nd₂NiO_4+δ (δ ~ 0.11); Sumit Ranjan Maity, Monica Ceretti, Lukas Keller, Juerg Schefer, Tian Shang, Ekaterina Pomjakushina, Martin Meven, Denis Sheptyakov, Antonio Cervellino and Werner Paulus; Physical Review Materials 2019, 3, 83604

(Nd/Pr)₂NiO_4+δ: Reaction Intermediates and Redox Behavior Explored by in Situ Neutron Powder Diffraction during Electrochemical Oxygen Intercalation; Monica Ceretti, Olivia Wahyudi, Gilles Andre, Martin Meven, Antoine Villesuzanne and Werner Paulus; Inorg. Chem. 2018, 57, 4657-4666

Funding:

This project Exploring oxygen diffusion mechanisms in Pr₂NiO_4+δ under in-situ conditions by neutron scattering: interplay between structure and lattice dynamics is a joint collaboration funded by the two following French and German funding agencies for scientific research:

Deutsche Forschungsgemeinschaft (DFG)

Grant Nr.: ME3488/2-1

Project number: 431446509

Project period: 01.10.2020 – 31.12.2023

Agence Nationale de la Recherche (ANR)

Grant Nr.: ANR-19-CE05-0041-01

Project period: 01.01.2020 - 31.12.2023