The Intermetalyst project aims to explore in details novel supported catalysts based on electride-like intermetallics RTX (R = rare-earth; T = transition metal; X = Si, Ge) to enhance the catalytic synthesis of ammonia and hence reduce its energy consumption. Electrides are crystals that contain excess electrons periodically located in crystallographic sites throughout the lattice. The ability of these RTX materials to transfer these electrons promotes the dissociation of an adsorbed molecule by weakening its chemical bond. This study is highly motivated by the discovery of the outstanding catalytic activity of the LaScSi silicide when combined with ruthenium. Besides, the very promising preliminary results obtained by the consortium for some other RTX intermetallics suggest that the LaScSi performances could be improved. The excellent catalytic activities of such type of materials are ascribed to their ability to supply electrons to Ru and absorb reversibly hydrogen in the working conditions of NH3 synthesis (N2+H2), preventing notably H poisoning of the Ru surface. Additionally, these materials are stable under ammonia synthesis conditions and do not necessitate high specific area. In this project divided in 5 Work Packages, we will synthesize these RTX intermetallics and determine their hydrogen sorption properties, as well as their electronic properties (including DFT calculations) and catalytic performances. The Intermetalyst project will be jointly led by experts of intermetallics and hydrides materials at ICMCB and specialists of catalysis at IC2MP. Finding stable non-toxic electrides materials, able to boost the Ru-based catalysis at ambient pressure as well as prevent the H poisoning of Ru, is a hot topic and will be a real breakthrough in the field of catalysis and sustainable chemistry.

Low cost strain sensors based on electron tunneling in assemblies of metallic nanoparticles (MNPs) are proposed as a new touch technology for flexible displays, but their sensitivity and stability are still impacted by variations in thickness, morphology and density of NPs films. With an industrial partner NANOMADE Concept, which develops a patented touch technology relying on MNPs-based resistive strain gauges, we propose to develop strain sensors based on the use of nanohelices assemblies coated with conductive nanoparticles interconnected via ligands to be advantageously used to overcome such critical points: the helical morphology exhibits enhanced flexibility that will increase the measurable range of strain; the positioning of metallic NPs with ligands on the nanohelices can be done with a high degree of precision; alignment of highly ordered wires of metallic NPs will be straightforward since they are already positioned on the nanohelices. The aim of this project is to improve the electromechanical properties of strain sensors both in terms of sensitivity as well as reproducibility and stability.

There is an increasing demand for high performance glass thin films (GTFs) for applications, such as microbatteries, electrochromic systems, photonics, biomaterials or protection against corrosion. In particular, lithium phosphorus oxynitride (LiPON) GTF is currently the commercial standard electrolyte for all-solid-state microbatteries, which are promising devices for a broad range of applications pertaining to communication, consumer electronics, products and people identification, traceability, security (bank transaction) as well as to smart environment and the internet of things. The major limitation of LiPON GTF is its limited Li+ conductivity, 3.3·10-6 S.cm-1 at 298 K, a value, which is 3 orders of magnitude lower than that of conventional Li-ion cells using liquid electrolytes. Recently it has been shown that the incorporation of a second former, such as SiO2, or sulfates in LiPON GTFs can dramatically enhance the ionic conductivity. Nevertheless, the composition space for these GTFs still needs to be explored and the rational improvement of the conductivity of these GTFs requires to better understand how these changes in the chemical composition affect the atomic-level structure and hence, the mechanism of Li+ conduction. The characterization of GTFs is challenging since they are amorphous, they contain multiple molecular patterns and their volume is small. This project aims at the rational improvement of the properties (ionic conductivities, chemical and thermal stabilities) of these innovative GTFs by determining the relationships between their chemical composition, their atomic-level structures and dynamics as well as their properties. We will explore the composition space of LiPON GTFs incorporating a second glass former, such as SiO2, or lithium sulfate. These GTFs will be prepared by radiofrequency (rf) magnetron sputtering. We will determine the effect of these composition changes on the local atomic-level structure and dynamics by developing and applying advanced solid-state Nuclear Magnetic Resonance (NMR) methods (small coils, high-field, paramagnetic doping…) suitable for the characterization of thin-films. Dynamic Nuclear Polarization (DNP) will also be employed to enhance the NMR signals of the surface nuclei and better understand the electrode/electrolyte interfacial phenomena. The medium-range positional order in the GTFs will be investigated by Transmission Electron Microscopy (TEM) and Pair Distribution Function (PDF) analysis. TEM and annular dark field scanning TEM (ADF-STEM) will be combined to image the structure of glass networks in glass ultra-thin films. PDF analysis will provide information about the bond length, the atom coordination numbers and the geometry. Finally the electrical and electrochemical properties of the GTF electrolytes, bare and integrated in microbatteries, will be measured. These properties will be correlated to the chemical composition and the atomic-scale structure and will be used to elaborate in a rational way GTF with optimized properties, including (i) Li+ conductivity > 10-5 S.cm-1, (ii) low electronic conductivity, (iii) low contribution to the overall cell impedance when integrated into microbatteries and (iv) good (electro)chemical and thermal stabilities, notably near the interface between GTF electrolyte and lithium metal electrodes. The ultimate long-term goals of the project are (i) to improve the performance of microbatteries and (ii) to change the way in which material scientists and chemists characterize GTFs used for various applications (electrolyte, coating…).

Because of their very light weight, excellent in-plane properties and high specific strength, Carbon Fiber-Reinforced Polymers has found many uses in structural applications. Nevertheless they are particularly prone to damage. These low energy shocks can occur during assembly phases in FAL (Final Assembly Line). Although damage is usually localized at the impact site, internal damages (delaminations, fibers to resin decohesion, transverse cracks) can be more widespread. Their propagation, under fatigue loading, can lead to serious issues like significantly compressive strength reduction. Moreover, impact damages can be subsurface or barely visible, necessitating expensive and time-consuming non-destructive inspection. Thus, a “visible” detection system will be very useful to focus ultrasonic inspection only where needed. In this context, CHOCOCOMP aims at developing, characterizing and assessing innovative impact sensitive and reversible coatings to detect and quantify damages on composite substrates. Piezochromic probes (ie: pigments that lead to color change under pressure) dispersed in hybrid polymeric/sol-gel matrix are promising candidates. Quantification of damage in composite will be used to calibrate impact energy/coating answer/substrate. Mechanical and chemical parameters will be correlated to ensure appropriate coating use with industrial application (manufacturing in FAL). I addition coating application process (spray), studied in parallel, fits with the current eco-efficiency trends strongly linked to production costs and cycles reduction. The strategy of this project will focus on 6 axes: -Relevant impact energy threshold definition to apply to the assembly “composite +coating” for creating damage in the composite part (calibration) -Design and optimization of piezochromic impact probes -Elaboration of impact sensitive and reversible coatings by the incorporation of the probes in a “home-made” hybrid polymeric/sol-gel matrix: combination of piezochromic properties, mechanical toughness and adhesion to substrates of the coatings -Impact probes and impact sensitive coatings characterization, led at macro- and microscopic scales -Performance assessment: mechanical behavior and shock sensitivity of the impact probes and sensitive coatings. Correlation with damages occurred in composite parts Quality evaluation of the interface coating/composite -Process optimization at pilot-scale of the best performing piezochromic probes. Spray-deposition method (appropriate viscosity range, pot life…) will be evaluated To date, this global scientific approach (chemical+mechanical+process) has not been investigated for damage indicating. CHOCOCOMP is a consortium, which draws together academic laboratories (LCMCP, ICMCB, P’UP, ENSMA-P’) to perform piezochromic pigments and the required coatings; and industrial companies including two SMEs (MAPAERO, OliKrom, EADS IW) to solve the specific industrial requirements. The complementarity of the expertise of each partner will allow delivering a composite substrate (250x250 cm2) coated with an impact-sensitive layer, at the end of the project. This coating will allow not only to detect shock, but also to quantify damages occurring in the composite substrate. Moreover, it will be possible to restore the coating at the initial stage by thermal constrain after US inspection of the impacted area. CHOCOCOMP is the 1st phase of pressure-sensitive coating development. The structure of the project sets to focus work on material and calibration for manufacturing applications. Results obtained will provide Go/NoGo criteria for a 2nd step dedicated to up-scale and industrialization. Moreover, results on such smart coatings could be extended, not only to aircrafts (launchers, helicopters, planes…) in service life, but also to other various applications as wind turbine blades, yaching, and many other industries and other substrates where impact detection is required (public works, motorcycle, sport)

The rare event searches in astroparticle physics by means of heat-scintillation cryogenic bolometers (HSCBs), the core of which is made of bulk crystals, is a rapidly expanding field that encompasses the quests for the basic particles of the dark matter (DM) halo of our galaxy and for the nature of the neutrino -that could possibly reveal a new type of matter-, and the spectroscopic exploration of the rare fast neutrons being the ultimate background found on DM direct detection in underground sites. It turns out that large Li2MoO4 single crystals, of mass in the range 350-500 g, would be excellent candidates to build such HSCBs capable to address two kinds of rare events: neutrinoless double beta decays (0n-DBD) and fast neutron backgrounds. We propose to grow not only larger Li2MoO4 crystals, but with unprecedented purity and quality, by means of both combined Czochralski pulling and modelling, single crystals characterizations and exploratory bolometer tests. CLYMENE will break down the boundary between crystal growers and astroparticle physicists and benefit from contributions of both communities converging towards a single interdisciplinary collaborative project. The main purpose of CLYMENE is to set the bases for versatile HSCBs capable of addressing the 0n-DBD detection and to pave the way for the development of a transportable fast neutrons cryogenic monitor. In the CLYMENE project, the feedback between scintillation measurements, detector performances (background) and crystal growth will enable the elaboration of one pilot natural Li2MoO4 crystal of mass 500 g, and three pilot Li2MoO4 crystals of similar masses, one of which will be enriched with 6Li isotope (95 %) and the remaining two will contain a considerable amount of enriched 7Li (99.9 %). The CLYMENE consortium is based on a synergetic interaction between experimented scientists of complementary research teams: a crystal growth laboratory, a growth process simulation laboratory, a crystal technology platform and an astroparticle physics laboratory.