165 research outputs found

    Transmission electron microscopy and ferromagnetic resonance investigations of tunnel magnetic junctions using Co2MnGe Heusler alloy as magnetic electrodes

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    HRTEM, nano-beam electronic diffraction, energy dispersive X-rays scanning spectroscopy, Vibrating Sample Magnetometry (VSM) and FerroMagnetic Resonance (FMR) techniques are used in view of comparing (static and dynamic) magnetic and structural properties of Co2MnGe (13 nm)/Al2O3 (3 nm)/Co (13 nm) tunnel magnetic junctions (TMJ), deposited on various single crystalline substrates (a-plane sapphire, MgO(100) and Si(111)). They allow for providing a correlation between these magnetic properties and the fine structure investigated at atomic scale. The Al2O3 tunnel barrier is always amorphous and contains a large concentration of Co atoms, which, however, is significantly reduced when using a sapphire substrate. The Co layer is polycrystalline and shows larger grains for films grown on a sapphire substrate. The VSM investigation reveals in-plane anisotropy only for samples grown on a sapphire substrate. The FMR spectra of the TMJs are compared to the obtained ones with a single Co and Co2MnGe films of identical thickness deposited on a sapphire substrate. As expected, two distinct modes are detected in the TMJs while only one mode is observed in each single film. For the TMJ grown on a sapphire substrate the FMR behavior does not significantly differ from the superposition of the individual spectra of the single films, allowing for concluding that the exchange coupling between the two magnetic layers is too small to give rise to observable shifts. For TMJs grown on a Si or on a MgO substrate the resonance spectra reveal one mode which is nearly identical to the obtained one in the single Co film, while the other observed resonance shows a considerably smaller intensity and cannot be described using the magnetic parameters appropriate to the single Co2MnGe film.Comment: 11 pages, 10 figures, Thin Solid Film

    When Does Expanded Eligibility Translate into Increased Take-Up? An Examination of Parental Leave Policy in Luxembourg

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    This article aims to explore the role of eligibility for parental leave as a determinant of access and as an enabler of leave take-up. To analyse the link between eligibility and take-up, we study a unique policy change in Luxembourg’s parental leave scheme. The country’s 2016 parental leave reform relaxed the eligibility criteria to enable marginal part-time working parents to access the parental leave scheme for the first time. We focus on this change and examine to what extent relaxing the eligibility criteria translated into increased take-up by the marginal part-time working parents who became eligible. To quantify this transition, we analyse trends in and patterns of eligibility for the scheme in Luxembourg between 2009 and 2018 among first-time parents working full-time, part-time, or marginal part-time hours. We use a subsample of Luxembourg-resident, cohabiting, first-time parents (N = 6,254) drawn from the social security data. Our analysis shows that as eligibility is dependent on individual factors, it has similarities among mothers and fathers, whereas take-up is notably greater for mothers. After the reform, we observe that marginal part-time working mothers started taking parental leave, but up to 2018, the reform’s outreach to marginal part-time working fathers remained limited. We also find that foreign national parents are less likely to be eligible for parental leave and have lower take-up rates. Despite the gendered parental leave take-up behaviours in parallel with international evidence, marginal part-time working mothers’ positive response to the reform indicates progress towards strengthening women’s labour market attachment in Luxembourg

    Magnetization dynamics in Co2MnGe/Al2MnGe/Al2O3$/Co tunnel junctions grown on different substrates

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    We study static and dynamic magnetic properties of Co2MnGe (13 nm)/Al2O3 (3 nm)/Co (13 nm) tunnel magnetic junctions (TMJ), deposited on various single crystalline substrates (a-plane sapphire, MgO(100), Si(111)). The results are compared to the magnetic properties of Co and of Co2_{2}MnGe single films lying on sapphire substrates. X-rays diffraction always shows a (110) orientation of the Co2_{2}MnGe films. Structural observations obtained by high resolution transmission electron microscopy confirmed the high quality of the TMJ grown on sapphire. Our vibrating sample magnetometry measurements reveal in-plane anisotropy only in samples grown on a sapphire substrate. Depending on the substrate, the ferromagnetic resonance spectra of the TMJs, studied by the microstrip technique, show one or two pseudo-uniform modes. In the case of MgO and of Si substrates only one mode is observed: it is described by magnetic parameters (g-factor, effective magnetization, in-plane magnetic anisotropy) derived in the frame of a simple expression of the magnetic energy density; these parameters are practically identical to those obtained for the Co single film. With a sapphire substrate two modes are present: one of them does not appreciably differ from the observed mode in the Co single film while the other one is similar to the mode appearing in the Co2_{2}MnGe single film: their magnetic parameters can thus be determined independently, using a classical model for the energy density in the absence of interlayer exchange coupling.Comment: 5 pages, 6 figure

    Demography and disorders of German Shepherd Dogs under primary veterinarycare in the UK

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    The German Shepherd Dog (GSD) has been widely used for a variety of working roles. However, concerns for the health and welfare of the GSD have been widely aired and there is evidence that breed numbers are now in decline in the UK. Accurate demographic and disorder data could assist with breeding and clinical prioritisation. The VetCompassTM Programme collects clinical data on dogs under primary veterinary care in the UK. This study included all VetCompassTM dogs under veterinary care during 2013. Demographic, mortality and clinical diagnosis data on GSDs were extracted and reported

    STEM nanoanalysis of Au/Pt/Ti-Si3N4 interfacial defects and reactions during local stress of SiGe HBTs

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    A new insight on the behavior of metal contact-insulating interfaces in SiGe heterojunction bipolar transistor is given by high-performance aberration-corrected scanning transmission electron microscopy (STEM) analysis tools equipped with sub-nanometric probe size. It is demonstrated that the presence of initial defects introduced during technological processes play a major role in the acceleration of degradation mechanisms of the structure during stress. A combination of energy-filtered transmission electron microscopy analysis with high angle annular dark field STEM and energy dispersive spectroscopy provides strong evidence that migration of Au-Pt from the metal contacts to Ti/Si3N4 interface is one of the precursors to species interdiffusion and reactions. High current densities and related local heating effects induce the evolution of the pure Ti initial layer into mixture layer composed of Ti, O, and N. Local contamination of Ti layers by fluorine atoms is also pointed out, as well as rupture of TiN thin barrier layer

    Live Coding, Live Notation, Live Performance

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    This paper/demonstration explores relationships between code, notation including representation, visualisation and performance. Performative aspects of live coding activities are increasingly being investigated as the live coding movement continues to grow and develop. Although live instrumental performance is sometimes included as an accompaniment to live coding, it is often not a fully integrated part of the performance, relying on improvisation and/or basic indicative forms of notation with varying levels of sophistication and universality. Technologies are developing which enable the use of fully explicit music notations as well as more graphic ones, allowing more fully integrated systems of code in and as performance which can also include notations of arbitrary complexity. This itself allows the full skills of instrumental musicians to be utilised and synchronised in the process. This presentation/demonstration presents work and performances already undertaken with these technologies, including technologies for body sensing and data acquisition in the translation of the movements of dancers and musicians into synchronously performable notation, integrated by live and prepared coding. The author together with clarinetist Ian Mitchell present a short live performance utilising these techniques, discuss methods for the dissemination and interpretation of live generated notations and investigate how they take advantage of instrumental musicians’ training-related neuroplasticity skills
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