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Investigation of nitrogen-vacancy centre creation and position control in thin single-crystal diamond films
No full textInternational audienceThe remarkable physical and chemical attributes of diamond have established it as a leading material for a wide array of applications. Its properties make it invaluable in areas such as optics, electronics, biomedicine, mechanics, and the rapidly evolving field of quantum technologies.A Distributed Antenna Array (DAA) microwave system (Fig. 1), comprising 16 plasma sources arranged in a 2D matrix, has been successfully used for the deposition of single-crystal diamond (SCD) layers using H2/CH4/CO2 and H2/CH4/O2 gas mixtures. Operating at low pressure (< 1 mbar), this system provides highly homogeneous plasma and low growth rates (< 100 nm.h⁻¹), ensuring precise control over layer thickness and defect positioning. Among these defects, colour centres, particularly nitrogen-vacancy (NV) centres, are of significant interest due to their promising applications in quantum technology. Precisely controlling their position within the diamond lattice is key for optimizing their performance in quantum devices.In this work, using this innovative reactor, we synthesized nitrogen-doped SCD films of approximately 100 nm in thickness by introducing N2 into the initial gas mixture. Our aim was to refine both growth and post-treatment processes to improve NV centre creation and spin properties. In particular, we explored a new growth procedure suitable for enhancing the efficiency of in situ NV formation while reducing reliance on post-growth treatments. We successfully reduced the thickness of this in situ nitrogen-doped layer down to 50 nm. NV⁻/NV⁰ photoluminescence intensities and spin coherence time (T2*) of the produced NVs were determined throughout the process, i.e. before and after SCD growth, and following post-treatments such as He implantation and annealing. This step-by-step approach enabled improved NV centre formation and properties, paving the way for more efficient quantum technologies and nanoscale sensing systems
Paul, Ludwig (with the cooperation of Pejman Firoozbakhsh): An Analytical Bibliography of New Iranian Languages and Dialects, Based on Persian publications since ca. 1980. Wiesbaden: Reichert 2022. € 98,00. ISBN 978-3-752-00608-7.
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Formal methodology for designing control laws to meet generalized marking constraints for partially controllable TEGs
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Extending mechanical size effect range of thin film metallic glasses by nanoengineering their atomic and nanostructure
No full textInternational audienceNanoscale metallic glasses (MGs) have demonstrated unique strength – ductility balance with a yield strength close to the theoretical limit and large homogeneous plastic deformation, mitigating the shear band (SB) instability. However, such mechanical size effects are triggered only for intrinsic sample dimensions below few hundreds of nm, reducing their application range. In this work, we present a novel synthesis strategy to fabricate nanostructured thin film metallic glasses (TFMGs) with tailored local heterogeneities by exploiting the potential of Pulsed Laser Deposition (PLD), managing to extend MG’s mechanical size effect range up to the micrometer scale. We realize this by synthetizing model Zr50Cu50 and Zr46Cu46Al8 TFMGs with controlled nanostructure compact and nanogranular, exploiting atom-by-atom and cluster-assembled growth regimes. PLD-deposited TFMGs have unique atomic structures as observed by synchrotron X-ray scattering, with high mass density, resulting in enhanced elastic modulus (up to 120 GPa) and hardness (up to 8.6 GPa), significantly above sputter-deposited counterparts. Moreover, PLD-deposited TFMGs exhibit high yield strength (σy >2.8 GPa) and up to 6.7 % elastoplastic deformation which are maintained even at high strain rates up to 10 s-1 for large micropillar dimension of 1.3 × 3 µm (diameter x height). Such values significantly surpass those of traditional families of bulk and TFMGs, where size effects on σy and plasticity are activated for intrinsic dimensions < 0.5 µm. Overall, we show that PLD can produce nanostructured TFMGs with high strength and plasticity balance kept for large intrinsic dimensions, opening a new synthesis approach for strong and ductile materials
Denser than diamond: Novel ultrahard orthorhombic C<sub>12</sub>
No full textInternational audienceTwo novel superdense carbon allotropes, orthorhombic C12 with 44T39 and dia topologies, belonging to the same space group Pna2C1 (No. 33), have been predicted from crystal structure engineering and DFT-based calculations of ground state structures and energy-derived properties. Both allotropes were found to be cohesive and mechanically stable with positive sets of elastic constants. The phonon band structures confirm that they are also dynamically stable. The Vickers hardness evaluated by various models qualifies both allotropes as ultrahard with H V values equal to (or in the case of 4C4T39 C12 , even higher than) that of diamond. While the new allotropes are metastable compared to diamond, their formation is possible at high pressures and high temperatures as a result of alternative metastable behavior. The electronic band structures indicate a transition from a semiconducting to an insulating state
Qualitative study of the experience of parents whose adolescent has been hospitalized for a suicidal episode: reshaping, mobilizing, and adapting
No full textInternational audienceA suicidal crisis is a set of symptoms that can occur frequently during adolescence. It can require hospitalization, a form of care that often also facilitates work with the adolescent’s parents, whose inclusion has proven beneficial. The objective of this work is to analyze parents’ experience of their adolescent’s suicidal crisis and hospitalization
Perforation of the Sigmoid Colon due to Diverticular Rupture in a Woman With <i>FKBP14</i>‐Related Kyphoscoliotic Ehlers‐Danlos Syndrome: A Case Report
No full textInternational audienceABSTRACT This report highlights that severe manifestations of intestinal fragility can occur in kyphoscoliotic EDS, as already described in vascular EDS
Evaluation of gut leakage and bacterial translocation as efficacy biomarkers of immunotherapy in advanced non-small cell lung cancer (NSCLC)
No full textInternational audienceDespite the therapeutic advancements achieved through immunotherapy [immune checkpoint inhibitors (ICIs)] in treating advanced non-small cell lung cancer (NSCLC), the majority of patients will experience tumor progression. There is an urgent need for new predictive biomarkers of ICI efficacy in this setting. Our study aims to demonstrate the role of gut leakage, evaluated by plasma citrulline, and bacterial translocation, through blood microbiome assessment, as predictive markers of response to ICIs in advanced NSCLC
Biomolecular ions generated by infrared laser desorption on microdroplets under vacuum
No full textInternational audienceA droplet beam-laser ablation gas phase source has been developed for the isolation of biomolecular ions ejected from liquid microdroplets under vacuum. Liquid microdroplets containing the biomolecular ions of interest are generated in a primary vacuum chamber and passed through differential pumping stages to interact with an infrared laser pulse in a secondary vacuum chamber. Absorption of the infrared radiation by the solvent causes the explosion of the droplets and the desorption of biomolecular ions into vacuum. These ions are then mass-analyzed by a homemade time-of-flight spectrometer, either through a delayed extraction line or through coupling with a Paul trap. We show that this desorption source allows for the transfer of fragile molecules into the gas phase and preserves small non-covalent complexes. It can be operated in the positive and negative modes. Mass spectrometry analysis by the coupling of the source with a Paul trap allows us to get rid of the broad initial velocity distribution of the desorbed species subsequently to the laser ablation and leads to an improved mass resolution. This is a very promising setup for the production of hydrated biomolecules. It opens the way to the subsequent gas phase structural analysis of the desorbed biomolecular ions
