The present project aims at developing a new model of the experimental spin resolved electron density common to experimental techniques as different as Polarised Neutron Diffraction (PND), high resolution X-Ray Diffraction (XRD), X-ray Magnetic Diffraction (XMD) and Magnetic Inelastic Compton Scattering (M-ICS). Thanks to methodological developments to which some of us participated, XRD and PND are now routinely used to determine the charge or spin densities in position space. XMD technique is an interesting alternative which complement polarised neutron diffraction; it is a powerful method for separating the orbital and the spin contributions to the magnetic diffraction. The Magnetic Compton scattering data give access to the spin resolved momentum density. In a previous ANR contract (CEDA, 2007-2011) we showed that the spin resolved electron density can be obtained by a joint refinement of polarised neutrons and high resolution X-ray diffraction data, by adapting the electron density multipole model. This allows for the very first time the experimental distinction between ? (spin up) and ? (spin down) electrons (Deustch et al, accepted to IUCrJ 2014). For atoms having spin and orbital moments, PND cannot distinguish between the two contributions, the orbital contribution being usually estimated from theoretical considerations. In order to have an experimental only spin density model, we want to bypass this theoretical estimation by including XMD. These three diffraction techniques give access to a more precise and accurate spin resolved distribution of localised electrons in position space. To complete the density model, the delocalised electrons can be more precisely determined using Compton scattering experiments (electron density in momentum space). Since these experiments can all be conducted on the same system, which means we are looking at the same object from different angles, our main objective is to construct a unique common physical model that exploits the richness of these scattering techniques. The common denominator for all these experiments is the 1 electron reduced density matrix (1RDM). Hence the aim of the project is to determine experimentally the elements (in a given basis set of atomic functions) of this matrix through a joint refinement against XRD, XMD, PND and ICS. The main problem of the joint refinement is to find a unique parameterisation common to all these techniques and to find a way to handle the variety and the precisions of the experimental data. In particular, this requires finding a proper weighting scheme and the refinement strategy, without losing any information coming from each experiment. The strategy will be defined using YTiO3 crystals, an interesting perovskite which shows orbital ordering not fully understood. As soon as the method is validated, it will be applied to suitable materials and the resulting software will be improved to be users friendly in order to distribute it to crystallographers, physicists and chemists.

The magnetic properties of nanostructures have been intensely investigated in the last few years since it offers the opportunity to unfold new physical phenomena and design novel devices and applications all at once. An example of such simultaneous progress of fundamental understanding and practical developments can be found in the recent trend consisting in the electrical manipulation of magnetic properties. This opens the way to the design of spintronics devices in which the application of some magnetic field is no longer necessary. Up to now, the research on this topic has essentially focused on manipulating the magnetization of ferromagnetic nanostructures, yet some recent theoretical results suggest that it is also possible to control the magnetic ordering in antiferromagnets (AF) with an electric field or a current, in a more efficient way than for ferromagnets. Antiferromagnets would then play an active role, and not merely act as complementary layers in complex stacking as they do in present devices. The aim of the ELECTR-AF project is to explore the physical mechanisms underlying the electrical control of AF ordering. To unravel the intrinsic phenomena, we choose to focus on model systems. We will focus on heterostructures build around chromium epitaxial thin films, since the AF ordering of bulk Cr is both well known and easy to manipulate. Indeed, high quality chromium samples exhibit a spin density wave (SDW) ordering, the period of the modulated structure being incommensurate with the crystalline lattice. These model AF layers will be included in model heterostructures: we will grow epitaxial bcc metal/MgO/bcc metal trilayers (Cr being either the top or bottom metallic layer). This class of system has played a crucial role in the detailed understanding of spin-dependent tunnelling, and we will thus be able to build on the accumulated knowledge to explore the physics of spin polarized transport in antiferromagnets. We will first carry out thorough studies of the magnetic properties of Cr thin films and of the Cr/MgO interface, in order to obtain a detailed knowledge of our system. We will follow two distinct strategies to manipulate the magnetic ordering of Cr layers: - we will apply a voltage across an MgO layer in order to accumulate charges at the Cr/MgO interface. Given the large sensitivity of Cr to doping, we expect to modify the SDW period. - we will flow a spin polarized current through a Cr layer. We expect to observe spin transfer torque effects, and thus induce switching or precession of Cr ordering parameter. To observe the evolution of Cr magnetic ordering with the external perturbation, we will combine diffraction and magnetotransport measurements. One challenge of this project is to obtain information on the elusive magnetic ordering of Cr. Neutron diffraction is the ideal tool to do so, since it gave direct access to the properties of the SDW (direction of propagation, period, polarization). This project will give us the impetus to push the limits of the technique. We will also use synchrotron-based techniques and benefit from the latest developments in terms of electronic microscopy. The experimental aspects of this project are thus highly ambitious, but we are plainly confident these challenging experiments can be done, in the light of feasibility tests we have run and recent developments in the different techniques.

Lubricating oils are being increasingly used across several industrial applications and the demand for these materials is on the rise and is expected to grow further in order to reduce machinery energy consumption and wear. Within this framework, the development of high performance lubricants is the key for the expansion of important industries and markets. Recently ionic liquids (ILs) have been shown to be promising candidates for novel high performances lubricants thanks to their various physico-chemical properties and their ability to lower significantly the friction between two surfaces. Such promising properties of ILs were found to be highly related to their capacity to nanostructure in bulk and at interfaces. However, the range of viscosities available in most IL classes is rather narrow compared to macromolecular lubricants. Poly(ionic liquid)s (PILs) are thus promising candidates to translate the frictional and chemical properties of both polymers and ILs to innovative and highly tuneable macromolecular lubricants. The addition of local interactions inherited from ILs to macromolecules results in a complex and rich panel of chemical and physical properties opening new opportunities to design polymeric materials with targeted functions which are highly related to both structural and dynamical properties of PILs. The POILLU project aims to take advantage of the lubrication properties of ILs and strong slippage ability of polymer melts to develop PILs with enhanced lubrication properties. Supported by the synthesis of a new class of tailored PILs specifically designed to meet the stringent criteria and ambitious objectives of this the project, this multidisciplinary consortium will perform a detailed molecular description of the bulk and interfacial stress transmission mechanisms involved in PILs using complementary state-of-the-art experimental techniques mastered by skilled soft matter physicists. The coupling of extensive bulk rheological characterization and advanced scattering techniques (SANS, WAXS) will enable us to determine the multi-scale structure/dynamic relationship occurring in PILs. The enhanced interfacial nano-structuration of PILs and its impact on surface chains dynamics will be studied thanks to Grazing Incident X-ray Scattering and Surface Force Apparatus nano-rheological measurements. Finally, the lubrication properties of PILs will be characterized using photobleaching based velocimetry technique. This interdisciplinary approach gathering internationally renowned skills in polymer chemistry, physical chemistry and physics that will highlight the exotic properties of PILs both in bulk and at interfaces opening appealing scientific perspectives in the field of complex polymeric materials targeting specific function through a multiscale molecular design.

Today and for some years to come, the development of batteries with high performance and safety at a low cost is the key for the expansion of important industries and markets such as electric vehicles and renewable energies. Lithium-metal polymer battery (LMP) technology is the most attractive one. Lithium-metal as anode shows specific capacity more than ten times that of LiC6 anode used in the widespread lithium-ion battery and is considered as the best to complement the positive air (O2) or sulfur cathodes. However, solid polymer electrolyte must be operated at 80°C to provide sufficient ionic conductivity, so that mechanical properties are weak with a limited electrochemical stability window. Furthermore, as in liquids, the fraction of charge carried by lithium ions is small (transference number 1000) and with a very limited dendritic growth. To reach these objectives, we propose a multidisciplinary approach gathering different complementary skills to design groundbreaking single-ion nanohybrid electrolytes able to afford different antagonist properties (i.e. high ion transport at RT and high mechanical strength). These materials are composed of ionic functional nanofillers (NFs) and amorphous polymer based on poly(ethylene oxide) (PEO). SELPHy project therefore devotes to: • The functionalization of NFs from various families (POSS, colloidal silica, cellulose nanofibers) with amorphous PEO short chains and/or lithium salt. • The formulation of single-ion nanohybrid electrolytes by blending functionalized NFs with an ionic conductor matrix, i.e. a crosslinked PEO based polymer. • The depth-characterizations of nanohybrid electrolytes including NFs dispersion state, (macro)molecular dynamics and macroscospic properties (transport and mechanical properties) in the aim to establish the structure-composition-macroscopic properties relationships. • The assembly of LMP battery prototype to qualify the new single-ion nanohybrid electrolytes. We are totally confident that our proposed single-ion electrolytes will exhibit: i) transference number close to 1 since the Li+ counter-ions are covalently grafted to the NFs, ii) High ionic conductivity (i.e. 10-4 S/cm at RT) thank to the high mobility of the amorphous PEO short chains grafted to the NF surface and the use of high lithium dissociated salt iii) Sufficient mechanical properties to encounter dendrites growth provided by the crosslinked polymer network and the NFs reinforcing capacity iv) High electrochemical stability up to 5 V vs Li+/Li (required for the battery comprising high potential active material) due to the grafting of the anions. v) Enhanced thermal stability for the safety thank to the presence of NFs like POSS. SELPHy is a collaborative research project involving three academic partners and interdisciplinary as it gathers indispensable expertise in organic and polymer chemistries, nanocomposite materials, physical chemistry, electrochemistry and electrochemical storage.

The non-covalent assembly of macromolecules in solution has been thoroughly investigated over the last decade with a particular emphasis put on the morphology of the final aggregates as a function of the building-blocks chemistry. While conventional studies often assume the equilibrium conditions, most real-world applications involve non-equilibrium assembly. Therefore, there is a real need to design tools and methodologies to control and understand the assembly of macromolecules under various thermodynamic conditions. Beyond the academic aspects of carrying out such research, this would be of general interest in polymer and material science. We propose in the PANORAMA project to study independently and systematically the impact of the processing route and interaction strength on the final morphologies and thermodynamic states of representative self- and co- assembled macromolecular systems (block copolymer aggregates, electrostatic assemblies of polyelectrolytes, nanoparticles, and proteins). The mixing time was selected as a relevant processing parameter to modify the initial conditions of assembly. By varying the mixing time from a few ms to more than one hour, a multitude of non-equilibrium systems can be generated. Scattering and microscopy techniques will help determining the morphology of the aggregates while isothermal titration calorimetry will be extensively used to gain more insight about the thermodynamic properties of the assembly. The formalization of the thermodynamic vs. morphology data can be a starting point for further modeling studies which is however beyond the scope of the current project. Furthermore, the possibility to achieve the macromolecular assembly close to equilibrium conditions will be put under scrutiny as well by turning off/on the driving interaction strength between components. Such an approach might result in the formation of unforeseen molecular structures and therefore highlights the paramount importance of the formulation pathway to guide the assembly process.