Dr. Mohamed Zbiri

This project is of a multifaceted nature and was built of cross-cutting topics related to energy and electronic organic materials. It is focused on the study of the local and vibrational structural dynamics of organic semiconductors - namely conjugated polymers and small organic molecules - using neutron spectroscopy measurements and numerical simulations. I designed and developed this project together with Anne Guilbertfrom Imperial College London. Following the topic, the selected publications below include contribution from coauthors from Queen Mary University of London and/or the University of Liverpool. 

^(*) Corresponding author(s)

M. Zbiri^(*), A. Guilbert^(*)
Dynamics of Polyalkylfluorene Conjugated Polymers: Insights from Neutron Spectroscopy and Molecular Dynamics Simulations
The Journal of Physical Chemistry B, 128 (2024) 6197

M. Zbiri^(*), C. Aitchison, R. Sprick, A. Cooper, A. Guilbert^(*)
Probing dynamics of water mass transfer in organic porous photocatalyst water-splitting materials by neutron spectroscopy
Chemistry of Materials, 33 (2021) 1363

A. Guilbert^(*), M. Zbiri^(*), P. Finn, M. Jenart, P. Fouquet, V. Cristiglio, B. Frick, J. Nelson, C. Nielsen
Mapping Micro-Structural Dynamics up to the nanosecond of the Conjugated Polymer P3HT in the Solid State ^(<>)
Chemistry of Materials, 31 (2019) 9635
^(<>) Selected as ACS's Editor's Choice as well as a main journal cover

A. Guilbert^(*), Y. Bai, C. Aitchison, R. Sprick, M. Zbiri^(*)
Impact of the chemical structure on the dynamics of mass transfer of water in conjugated microporous polymers: A neutron spectroscopy study
ACS Applied Polymer Materials, 3 (2021) 765

M. Zbiri^(*), P. Gilhooly-Finn, P. Fouquet, C. Nielsen, A. Guilbert^(*)
Structural Dynamics of Polymer:Non-Fullerene Organic Solar Cell Blends: A Neutron Spectroscopy Perspective
Chemistry of Materials, 34 (2022) 7937

A. Guilbert^(*), M. Zbiri^(*), M. Jenart, C. Nielsen, J. Nelson
New insights into the molecular dynamics of P3HT:PCBM bulk heterojunction: A time-of-flight quasi-elastic neutron scattering study
The Journal of Physical Chemistry Letters, 7 (2016) 2252

A. Guilbert^(*), Z. Parr, T. Kreouzis, D. Woods, R. Sprick, I. Abrahams, C. Nielsen, M. Zbiri^(*)
Effect of substituting non-polar chains with polar chains on the structural dynamics of small organic molecule and polymer semiconductors
Physical Chemistry Chemical Physics, 23 (2021) 7462

M. Zbiri^(*), P. Finn, C. Nielsen, A. Guilbert^(*)
Quantitative insights into the phase behaviour and miscibility of organic photovoltaic active layers from the perspective of neutron spectroscopy
Journal of Materials Chemistry C, 9 (2021) 11873

A. Guilbert^(*), M. Zbiri^(*), A. Dunbar, J. Nelson
Quantitative Analysis of the Molecular Dynamics of P3HT:PCBM Bulk Heterojunction
The Journal of Physical Chemistry B, 121 (2017) 9073

This project dealt with the study of structure, dynamics and electronics of a discotic liquid crystal charge transfer complex using mostly neutron scattering and numerical simulations. The following contributions gather publications authored together with Lucas Haverkate (PhD student), Fokko Mulder and Gordon Kearley from Delft University of Technology, and Mark Johnson from the ILL.

^(*) Corresponding author(s)

M. Zbiri^(*), L. Haverkate, G. Kearley, M. Johnson, F. Mulder
Book Chapter: Organic Solar Cells
In: Neutron Applications in Materials for Energy
Series: Neutron Scattering Applications and Techniques
Ed. Springer (2015)

M. Zbiri^(*), L. Haverkate, G. Kearley, M. Johnson, F. Mulder
Structure and Dynamics of a Model Discotic Organic Conducting Material ^(><)
Journal of Physics: Conference Series, 758 (2016) 012012
^(><)Peer-reviewed proceeding publication of a talk I gave at the 3rd Euro-Mediterranean Conference on Materials and Renewable Energies

In this project I led its dynamics side focused on the use of inelastic neutron scattering and first principles lattice dynamical calculations to study phonons in negative thermal expansion transition metal cyanide frameworks with various dimensional and disorder aspects. The project included Stella d'Ambrumenil as a PhD student under my supervision at the ILL, in collaboration with coauthors from the University of Reading and the University of Oxford.

^(*) Corresponding author(s)

S. d’Ambrumenil, M. Zbiri^(*), S. Hibble, A. Chippindale, D. Keeble, C. Wright, N. Rees
Anomalous thermal expansion in one-dimensional transition metal cyanides: Behavior of the trimetallic cyanide Cu_1/3Ag_1/3Au_1/3CN
Physical Review B, 100 (2019) 174302

S. d'Ambrumenil, M. Zbiri^(*), A. Chippindale, S. Hibble
Phonon dynamics in the layered negative thermal expansion compounds Cu_xNi_2-x(CN)₄
Physical Review B, 100 (2019) 094312

S. d'Ambrumenil, M. Zbiri^(*), A. Chippindale, S. Hibble, E. Marelli, A. Hannon
Lattice dynamics and negative thermal expansion in the framework compound ZnNi(CN)₄ with two-dimensional and three-dimensional local environments
Physical Review B, 99 (2019) 024309

This project is built of topics sharing at least a common theme in terms of phonons and their interplay/coupling with magnetism in materials exhibiting the below specified remarkable properties. Another aspect these topics do have in common is the use of inelastic neutron scattering and ab initio calculations as master methods of the studies. The publications below included contribution from coauthors through different collaborations.

^(*) Corresponding author(s)

Fe-based High-Temperature Superconductors

M. Zbiri^(*), W. Jin^(*), Y. Xiao, Y. Sun, Y. Su, S. Demirdis, G. Cao
Absence of magnetism in the superconductor Ba₂Ti₂Fe₂As₄O: Insights from inelastic neutron scattering measurements and ab initio calculations of phonon spectra
Physical Review B, 95 (2017) 174301

M. Zbiri^(*), R. Mittal, S. Rols, Y. Su, Y. Xiao, H. Schober, S. L. Chaplot, M. Johnson, T. Chatterji, Y. Inoue, S. Matsuishi, H. Hosono, Th. Brückel
Magnetic Lattice Dynamics of the Oxygen-Free FeAs Pnictides: How Sensitive are Phonons to Magnetic Ordering?
Journal of Physics: Condensed Matter, 22 (2010) 315701

M. Zbiri^(*), H. Schober, M. R. Johnson, S. Rols, R. Mittal, Y. Su, M. Rotter and D. Johrendt
Ab initio lattice dynamics simulations and inelastic neutron scattering spectra for studying phonons in BaFe₂As₂: Effect of structural phase transition, structural relaxation and magnetic ordering
Physical Review B, 79 (2009) 064511

Y. Xiao^(*), M. Zbiri^(*), J.-W. G. Bos, Th. Brückel, T. Chatterji^(*)
Inelastic neutron scattering study of crystal field excitations of Nd³⁺ in NdFeAsO
Physical Review B, 88 (2013) 214419

M. Zbiri^(*), R. Viennois
Phonon Spectra in the Parent Superconducting Iron-tuned Telluride Fe_1+xTe from Inelastic Neutron Scattering and Ab Initio Calculations
Physical Review B, 96 (2017) 134304

Frustrated Magnets

M. Zbiri^(*), H. Mutka, M. Johnson, H. Schober, C. Payen
Phonon Control of Magnetic Relaxation in the Pyrochlore Slab Compounds SCGO and BSZCGO
Physical Review B, 81 (2010) 104414

M. Zbiri^(*), T. Fennell, J. Taylor, M. Enderle, G. Lau, R. Cava, M. Johnson
Ab initio lattice dynamics calculation of vibrational density of states and Raman active modes of the olivine mineral Ni₂SiO₄
Journal of Physics: Condensed Matter, 20 (2008) 285203

Some multiferroics ...

M. Zbiri^(*), H. Schober, N. Choudhury, R. Mittal, S. L. Chaplot, S. J. Patwe, S. N. Achary, A. Tyagi
High-Temperature Phonon Spectra of Multiferroic BiFeO₃ From Inelastic Neutron Spectroscopy
Applied Physics Letters, 100 (2012) 142901

Using neutrons to explore the secrets of greener hydrogen fuel production

Towards improved plastic solar cells

Identifying molecular processes involved in the electrical conductivity aspects of organic semiconductors

Mapping the microscopic behaviour of conjugated polymers

Exploring water-splitting photocatalysts with neutrons

Neutron spectroscopy helps pave the way for greener hydrogen fuel production

The magnetism of high spin cobalt(II) ions in square planar coordination   (p. 028-029)

Magnetic oxygen and vanadium sites in the kagome staircase material Co₃V₂O₈   (p. 62-63)

Quasi-elastic neutron spectroscopy sheds light on the molecular dynamics of organic photovoltaic solar cells

Insights into the unusual phenomenon of negative thermal expansion: Relevancy to dynamics   (p. 66-67)

Formation and coupling of collective spins in an array of frustrated nano-magnets: experiment and simulation   (p. 064-065)

Dancing discotic molecules for self-assembled electronic devices   (p. 64-65)

A high-pressure neutron-scattering study sheds light on the stability, compressibility and phase transitions in Ni(CN)₂

Crystal field excitations in NdFeAsO: another magnetic aspect of the Fe - pnictides   (p. 20-21)

An (almost) perfect two-dimensional Brownian gas

Neutron scattering sheds light on the structural dynamics of semiconducting organic materials for energy applications

First-principle calculations reveal how in BaFe₂As₂ electrons interact with phonons through their spin   (p. 60-61)

Quasi-elastic neutron spectroscopy sheds light on conjugated microporous polymers as potential water-splitting photochemical catalysts

Contributions to the ILL topical brochure on :

Neutrons and Energy

Therein, authoring the introductory article (p. 4) "New materials for sustainabale energy" and the article (p. 10)"Liquid-crystal solar cells". Also a member of the research team of the article (p. 17) "A close look into friction and lubrication".

Journal covers related to some of my representative works described above :

Structural Dynamics of Conjugated Polymer and Small Organic Molecule Semiconductors

Chemistry of Materials

Structural Dynamics of Discotic Liquid Crystal Charge Transfer Complexes

The Journal of Physical Chemsitry B

I've taken part in coordinating and organizing the ILL's contribution and participation in several editions of the UK Neutron and Muon Science and User Meeting (NMSUM). NMSUM takes place yearly at the Warwick University Conference centre. This event includes plenary lectures, parallel sessions, a dedicated student day and an update on the large scale research facilities. Additionally, I was also particularly involved in the co-organization of the session on Functional Materials and the student day (e.g. here).

The role of a college secretary includes organizing seminars given by invited speakers. The table below gathers some general seminars which were organized during my term as the College 7 scientific secretary.