Pascal Roussel

Solid State Chemistry Department
Inorganic materials, structures, systems and prope (MISSP)


Directeur de recherches

(Faculty and CNRS researchers)


Office:206 (buiding C7)
Phone:(+33) 03 20 05 87 33
Mail:This email address is being protected from spambots. You need JavaScript enabled to view it.
Address:Ecole Nationale Supérieure de Chimie de Lille
Cité Scientifique, Bâtiment C7 - BP 90108
59652 Villeneuve d'Ascq Cedex
France

 

Orcid Id : 0000-0001-7243-7293

Keywords: Solid State Chemistry, Crystallography, Diffraction (X-ray, neutrons, electrons), complex structures (modulated, anharmonicity, twin), pseudo-symmetry, order-disorder, thin films

 

Academic training

  • 2012-present: CNRS Research Director, UCCS (Catalysis and Solid State Chemistry Unit), CNRS UMR8181, Lille
  • 2000-2012: CNRS Research Scientist, LCPS (Crystal Chemistry and Physic Laboratory), CNRS UMR8012, Lille
  • 2008: Habilitation – Solid State Chemistry Specialization - University of Lille: "Modeling of order-disorder phenomena in solids: contribution of X-ray and neutrons diffractions". Jury: C. Lecomte (Chair), M. Anne (Referee), G. Heger (Referee), A. Maignan (Referee) & F. Abraham (Director of Research)
  • 1999-2000: Post-doctoral fellowship at the Institute for Kristallography in Aachen, Germany (Director: Prof. Gernot Heger): "Use and development of a prototype high resolution four-circle single crystal diffractometer."
  • 1995-1999: PhD – Solid State Chemistry Specialty - University of Caen: "Crystallogenesis and structural studies of tungsten phosphate bronzes (PO2)4(WO3)2m and Ax(PO2)4(WO3)2m (A= Na, K, Pb) : Modulations and charge density waves". Jury: J.P. Pouget (Chairman), C. Lecomte (Referee), J.L. Hodeau (Referee), Ph. Labbé (Co-supervisor of Thesis), D. Groult (Co-supervisor of Thesis) & B. Raveau
  • 1994-1995: Master – Materials Sciences – University of Caen

Scientific contribution

My research activity is oriented towards crystallography and structure-property relationships in new materials with remarkable properties. Whether during my thesis, post doctoral studies or today at UCCS, structural studies (whether on single crystal, powder, thin films, X-ray, neutron or recently electron diffraction) constitute the most important part of my work. Although this step is not an end in itself, it allows us to better address the last step, namely the study, understanding and optimization of the physical properties of new synthesized materials. However, in many cases, there are order (or disorder) issues that complicate (and spice up) the structural study. It is often in these "unconventional" cases that I rise. When we talk about "unconventional" cases, we talk about formalisms and therefore "unconventional" crystallography, which sums up quite well my role in the laboratory. Already, at the time of my recruitment to the CNRS, the key word that summarized my profile was "transversality" within the different teams. This is still true today and my research activity is by definition quite varied, although I save time to conduct my own research subjects in the development of unconventional crystallography methods.

Recently, we can mention all the developments in electron crystallography, from acquisition in tomography mode in reciprocal space, to structural refinement by considering the dynamic theory of diffraction. This theme, initiated in 2006 by ANR SONDE, is now mature in the sense that it is now possible to solve and refine structures on objects of nanometric size with an accuracy comparable to that of the Rietveld method. This theme has allowed me to make very fruitful contacts with Lukas Palatinus, from the Czech Academy of Sciences, who developed the data extraction and integration part and especially the implementation of dynamic theory in the structural refinement software JANA2006. I have had the opportunity to give several invited lectures at international conferences on this theme.

I have also developed "exotic" approaches to interpret the order/disorder that causes the ionic conduction properties of SOFC fuel cell materials. Thus I was confronted with incommensurable modulated structures (solved during Vaclav Petricek's periods as a visiting professor in Lille, specialist in this approach and author of the software, JANA2006), I was confronted with the anharmonic developments of the thermal agitation tensor to evaluate activation energies and the Maximum entropy method, for example to image a disorder causing remarkable magnetic properties.

I took advantage of the arrival of a rotating anode diffractometer to specialize in the structural study of epitaxial thin films. I had to learn new concepts such as reciprocal space mapping, interpretation of pole figures or X-ray reflectivity. This has been very beneficial, both for me and for my colleagues in deposition, as it has allowed us to achieve interesting results on 3D Li-ion microbatteries. This theme, which is very competitive in terms of impact factor (3 Adv Energy Mat, 1 Adv Funct Mat, 2 Chem Mat, 2 Energy Storage Mat), is however very competitive... It also allowed me to join a particularly interesting collaboration network, at the origin of the ANR CASSIOPES obtained in 2018 on Advanced Characterization in Situ - OPerando de micro-batteriES.

Finally, I think I have made myself a speciality in solving complex structures (twinned and/or disordered) which, although not a theme as such, often makes it possible to unblock a difficult situation and to trace back to the relationships between structure and properties (indeed, no correct structure, no starting point for a plausible explanation).

 

Bibliometric analysis

  • 245 publications published (+ 41 conference proceedings published in special issues of peer-reviewed journals)
  • 1 book + 4 book chapters
  • 7 couvertures (2 J. Solid State Chem., 2 Chem Comm, 1 Solid State Sciences, 1 Zeit. fur Kristallographie, 1 Eur J Inorg Chem)
  • 19 conference proceedings published without a reading committee
  • 142 papers presented at international congresses (including 28 posters)
  • 92 papers presented at national congresses (including 30 posters)
  • 41 invited conferences, 13 as speakers (9 international +4 national)
  • 14 invited seminars (9 abroad, 5 in France)

H factor of 35 for 4426 total citations (source Google Scholar, July 20, 2019) 

 

Choice of 5 significant publications

  1. Illustrates recent developments in electron crystallography, especially the contribution of refinement by taking into account residual dynamical effects:

M. Colmont, L. Palatinus, M. Huve, H. Kabbour, S. Saitzek, N. Djelal & P. Roussel (2016) Inorg. Chem. 55 p2252-2260,

"On the use of dynamical diffraction theory to refine crystal structure from electron diffraction data. Application to K1La5O5(VO4)2, a material with promising luminescent properties." DOI : /10.1021/acs.inorgchem.5b02663

 

  1. Illustration of the contributions of advanced X-ray diffraction for the development of 3D micro-batteries:
 

M. Létiche, M. Hallot, M. Huvé, Th. Brousse, P. Roussel & Ch. Lethien (2017) Chem Mat. 29 (14), p6044-6057

Relationship between deposition pressure and cation ordering in sputtered LiMn1.5Ni0.5O4 thin film deposited on functional current collectors for Li-ion microbattery applications”.

DOI : 10.1021/acs.chemmater.7b01921

 

  1. Illustration of the complementarity between diffractions (X-ray, neutrons, electrons) and DFT calculations, contribution of MEM:

Z.L. Moreno-Botello, A. Montenegro, N. Grimaldos Osorio, M. Huvé, C. Pirovano, D.R. Småbråten, S.M. Selbach, A. Caneiro, P. Roussel & G.H. Gauthier (2019) J. Mat. Chem. A 7, 18589-18602
"Pure and Zr-doped YMnO3+delta as YSZ-compatible SOFC cathode: a combined computational and experimental approach." DOI : 10.1039/C9TA04912F

 

  1. Example of complex structural resolution (incommensurability, twin, pseudo-symmetry):