Alloying design of multiple components solid solution alloys defined originally as high-entropy alloys (HEAs) emerges as a powerful strategy to develop new materials with enhanced properties. The HEAs have been attracting extensive attention due to their unique compositions, microstructures, and good mechanical properties, such as high strength, high ductility and high fracture toughness in a large temperature range. However, depending on their actual composition, they may present complex microstructures which affect the link between the parameters of thermomechanical treatments and their deformation mechanisms in a complex and still unclear way. The first set of objectives of the HEMA project will be to elaborate and evaluate the mechanical properties under various loading conditions of some refractory HEAs (TiHfZrNbTa system) to be first used as structural materials. The local deformation mechanisms and the effect of local chemistry variations or short range ordering will then be investigated and modelled. Thermal stability of the microstructures subjected to high temperature mechanical loading will also be studied in order to bring some information about recrystallization mechanisms in these materials. Also, as the TiHfZrNbTa system is an ideal candidate to obtain other interesting properties, the second set of objectives will be to obtain several multifunctional TiHfZrNbTa—HEAs by fine-tuning the alloy composition, for e.g.
• Severe industrial environments (such as petrochemical/nuclear plants or high temperature conditions), for which enhanced structural properties are necessary combined with auto-cleaning or refractory and corrosion properties ;
• Biomedical applications : low modulus TiHfZrNbTa—HEAs may present a better biocompatibility for an in vivo use (including their biopolymeric coating) than the well-known Ti-6Al-4V alloy
• And possibly, electromagnetic applications considering the type-II supraconductor properties of NbTa based alloys or the spintronic properties of HfZr based ones.
The present project aims at gathering various skills within the LABEX SEAM in elaboration, characterization and modelling in order to develop multifunctional HEAs and to investigate the following steps : (i) the development and microstructural and mechanical characterization of some new retained compositions (ii) the identification and modelling of the basic mechanisms acting during thermomechanical processing, (iii) the evaluation of the electromagnetic properties of some of the selected alloys (NbTa or HfZr rich alloys) and (iv) the functionalization of the selected materials for specific applications (polymer coating for biocompatibility, controlled surface oxidation for photocalaytic properties, surface patterning for self-cleaning capabilities…).

The goal of the P2M project is to combine, within the LabEx SEAM (Partners : ITODYS, MSC, LPL), the scientific knowledge and the technical know-how necessary to solve the issues that show up when printing functional materials on fibrous substrates. This process is the first crucial step in the manufacture of smart devices (e-textile, e-paper). The development of new printing methods (large areas) of structural materials with a wide resolution range (from a few nm to the μm) would definitely represent a step forward and could have important repercussions for both the academic and industrial environment. The combination of complementary fields of expertise existing within the LabEx SEAM allows to propose a transversal and innovative approach to address the problem of inkjet-printing resolution from different standpoints. The project P2M is divided in 3 work packages : (Task 1), ink spreading on the substrate surface : modelling and prediction ; (Task 2), Substrate functionalisation methodologies and (Task 3), nanostructured inks. The expertise and scientific knowledge shared between the project partners oriented towards the improvement of printing fabrication techniques will allow to reach important scientific achievements and breakthrough, directly exploitable by the LabEx partners in their own field(s) of applications. Besides this local implications, and considering the interest clearly manifested by the industrial sector, all the results regarding the controlled introduction of high added value functionalities onto fibrous substrates have a considerable valorisation potential (increase of innovation capacity, creation of new market opportunities). The structuring nature of the P2M project is clearly expressed both through its technical (i.e., expansion of the fabrication processes know-how available within the LabEx SEAM) and scientific scope (i.e., harmonisation of different sorts of complementary expertise around a scientific theme which is open and dynamic). Our long term objective is the creation of an extended consortium (including industrial partners) allowing the fabrication and commercialisation of prototypes starting from the basic research results obtained thanks to the LabEx sponsorship.

During 2015 we have set up a fabrication process of Aluminium Gallium Arsenide (AlGaAs) layers on top of a good-quality optical substrate of Aluminium Oxide (AlOx). This has enabled us to enter the very young, promising and competitive domain of semiconductor nanophotonics, with the first demonstration of second harmonic generation in a nanoantenna. Non-plasmonic nanophotonics is raising a strong interest, because the optical response of high-permittivity dielectric nanoparticles in a low refractive-Index environment shows negligible dissipative losses and strong multipolar magnetic resonances in the visible and near infrared. Whereas some very interesting results have been demonstrated in the silicon-oninsulator platform in the last two years, the monolithic AlGaAs-on-AlOx system provides an ideal choice for nanophotonics thanks to several strong points of AlGaAs with respect to silicon, among which the χ(2) nonlinearity and a direct gap that is both larger and variable with the aluminium molar fraction. By combining the complementary competences of four groups within the Labex, we aim at two AlGaAs-on-AlOx demonstrators of strong scientific impact : 1) a highly efficient nonlinear metasurface ; and 2) a metasurface for surface-enhanced spectroscopies.

This structuring project concerns molecular spintronics. It aims to structure a new and pluridisciplinary research activity around this emerging topic within the SEAM Labex. It gathers several laboratories and teams from the University Paris Diderot and the University Paris 13 that have already collaborated with success in the past. Here, the scientific goal is to realize and to study the chemical, electronic, magnetic and spin transport properties of hybrid heterostructures based on carbon nanotubes, ferromagnetic metals and molecules. A main aspect will be the study of ferromagnetic metals filled carbon nanotubes as a spin nano-source integrated in spintronics devices like magnetic tunnel junctions and spin valves. This project will be conducted with a promising multi-scale approach yet unobserved worldwide. The different physical and chemical properties will be probed at the molecular scale thanks to scanning tunneling microscope and at the microscopic scale thanks to transport measurements in devices and to a powerful optical spectroscopy technique named Brillouin spectroscopy. We propose also a static approach followed by a dynamical one to ensure a deep understanding (a key element for further industrial transfer) of such promising mixture of different materials. Finally, we want to put forward the various skills and strenghts existing within the SEAM Labex with an exciting scientific project.

The project thereafter presented aims to aggregate some of the SEAM LABEX existing numerical codes, to get a tool able to perform both multi-scale and multi-physic computations. The tool we aim to develop is supposed to be an upgradable one, as well as multipurpose and easy to use. We Would like to first focus the application of such a tool on surfaces and interfaces studies, for they becomes more and more the key point of industrial applications (in Term of function, and then, reliability). We would like to use two federative subjects for some Labex research teams to launch this numerical global tool development : the first one deals with metal hydrogen embrittlement, the second one on contact line propagation. These Two subjects, sharing a lot of theoretical concepts, are multi-scales (and Potentially multi-physic) by nature. Experimental investigations Linked to these problematic are, last, currently studied by Labex Research teams, leading to a double level structuration effect : on the one hand, the federation of modeling tasks and tools, initially begin developed for a given purpose without any further connections, and more globally, on the second hand, by the opportunities such a multi-purpose modeling tool might lead, in term of experimental results understandings.

Fabricating plasmonic - ; magnetic nanoparticles (NPs) is a new challenge in material sciences, because such nanostructures would be promising candidates for many applications in medical imaging and cancer treatment by hyperthermia. The PlasMag project focuses on the development and the practical use of FexOy/Au nanohybrids for both magnetic and plasmonic hyperthermia and as a dual MRI and CT scan imaging contrast agent. In a first place, our multidisciplinary consortium composed by research’s teams from the four laboratories of the SEAM Labex, will work on the fabrication of nanohybrids with technologically relevant magnetic and plasmonic properties. This fundamental aspect of nanomaterial developments requires studying the close link between the atomic structure and the physical properties of NPs. Through collaborative efforts with medical research groups and industrial partners we will undertake applicative studies on the utilization of nanohybrids for thermal ablation of tumors by magnetic and plasmonic hyperthermia and the most used in vivo imaging techniques in hospitals (MRI and X-ray computed tomography). The most innovative aspect of this project is the study of the interaction between NPs and their application medium (cellular environment). Indeed, these interactions are of primary importance because they could alter the properties of the NPs and be toxic for the patient. Based on our knowledge and knowhow in material science, we proposed new nano-metrological methods to detect and quantify biotransformation and biodegradation processes of nanomaterials in the organism, from the macroscopic down to the atomic scale. Therefore, we intend to understand the relation between the structure and the life cycle of nanomaterials in the organism, which is the key to creating efficient and safe -nanomedicines- in their application environments.

The Project CAPTURE aims at the development of innovative devices for the mid and far infrared domains (THz spectral range) based on diamond technological platform. The device architectures that we will develop combine strong sub-wavelength confinement of the infrared radiation and an increased coupling efficiency with the free space through the use of antennas. On one hand, the use of heavily doped diamond layers allows the achievement of new electrically pumped sources of THz radiation where emission of confined plasmons is enhanced through microcavity effects. On the other hand, such architectures will enable the integration of optomechanical elements with the THz cavities for an efficient transduction between the far-infrared and visible wavelengths, in order to obtain a new detection method of the THz waves. This project relies on the dynamic collaboration between the QUAD and DON teams from MPQ and the PEMA team from LSPM, each of them bringing their well-recognised know-how respectively in the fields of THz optoelectronics, optomechanics and diamond growth.