Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems

We present the science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems, targeting an evolution in technology, that might lead to impacts and benefits reaching into most areas of society. This roadmap was developed within the framework of the European Graphene Flagship and outlines the main targets and research areas as best understood at the start of this ambitious project. We provide an overview of the key aspects of graphene and related materials (GRMs), ranging from fundamental research challenges to a variety of applications in a large number of sectors, highlighting the steps necessary to take GRMs from a state of raw potential to a point where they might revolutionize multiple industries. We also define an extensive list of acronyms in an effort to standardize the nomenclature in this emerging field.Peer ReviewedPostprint (published version

Interface growth mechanism in Ion Beam Sputtering deposited Mo/Si multi-layers

International audienceDespite the technological importance of Metal/Si multilayer structure in Microelectronics, the interface reactions occurring during their preparation are not fully understood, yet. In this work, the interface intermixing in Mo/Si multilayer coatings has been studied with respect to their preparation conditions. Various samples prepared at room temperature with different Mo deposition rates (0.06-0.43 Å/s) and a constant Si one have been investigated by detailed TEM observations. Contrary to the Si-on-Mo interface where no evidence of chemical intermixing could be found, the Mo-on-Si interface presents a noticeable interface zone whose thickness was found to noticeably decrease (from 4.1 to 3.2 nm) when increasing the Mo deposition rate. Such intermixing phenomena correspond to diffusion mechanisms having coefficients ranging from 0.25 to 1.2.10-15 cm²/s at room temperature. By assuming a diffusion mechanism mainly driven by Mo-Si atomic exchanges to minimize the surface energy, the diffusion dependence with Mo deposition rate has been successfully simulated using a cellular automaton. A refined simulation including Mo cluster formation is also proposed to explain the scenario leading to the full crystallisation of Mo layers

Influence of litter size on metabolic status and reproductive axis in primiparous sows

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Stress characteristics in EUV mask Mo/Si multilayers deposited by ion beam sputtering

International audienceThe stress evolution of IBS-deposited Mo and Si 100-nm-thick films has been investigated. Mo films’ compressive stress decreases from −2550 MPa to −1000 MPa as the sputtering gas changes from Ar to Xe, whereas Si films’ stress remains constant around −850 MPa whatever the sputtering gas. Then the stress behaviour of Mo/Si multilayers sputtered either with Ar or Xe has been observed. In both cases, the multilayer stress first becomes less compressive and then increases, as Mo thickness in the multilayer increases. However, like in the single layer case, the level of stress strongly depends on the sputtering gas. The multilayers sputtered with Xe even become tensile. Moreover, the analysis of the contraction of the multilayers led us to the conclusion that a Mo/Si interface grows, but in a different way, depending on the sputtering gas. Possible stress-generating mechanisms during growth of these multilayers as well as single layer films of Mo and Si are discussed

Roughness and light scattering of ion-beam-sputtered fluoride coatings for 193 nm

Scattering characteristics of multilayer fluoride coatings for 193 nm deposited by ion beam sputtering and the related interfacial roughnesses are investigated. Quarter- and half-wave stacks of MgF2 and LaF3 with increasing thickness are deposited onto CaF2 and fused silica and are systematically characterized. Roughness measurements carried out by atomic force microscopy reveal the evolution of the power spectral densities of the interfaces with coating thickness. Backward-scattering measurements are presented, and the results are compared with theoretical predictions that use different models for the statistical correlation of interfacial roughnesses

Procedure to characterize microroughness of optical thin films: application to ion-beam-sputtered vacuum-ultraviolet coatings

A method for characterizing the microroughness of samples in optical coating technology is developed. Measurements over different spatial-frequency ranges are composed into a single power spectral density (PSD) covering a large bandwidth. This is followed by the extraction of characteristic parameters through fitting of the PSD to a suitable combination of theoretical models. The method allows us to combine microroughness measurements performed with different techniques, and the fitting procedure can be adapted to any behavior of a combined PSD. The method has been applied to a set of ion-beam-sputtered fluoride vacuum-UV coatings with increasing number of alternative low- and high-index layers. Conclusions about roughness development and microstructural growth are drawn