Unexpected Magnetism of Small Silver Clusters

The ground-state electronic, structural, and magnetic properties of small silver clusters, Ag$_n$ (2$\le$n$\le$22), have been studied using a linear combination of atomic Gaussian-type orbitals within the density functional theory. The results show that the silver atoms, which are diamagnetic in bulk environment, can be magnetic when they are grouped together in clusters. The Ag$_{13}$ cluster with icosahedral symmetry has the highest magnetic moment per atom among the studied silver clusters. The cluster symmetry and the reduced coordination number specific of small clusters reveal as a fundamental factor for the onset of the magnetism.Comment: 4 pages, 4 figure

Hotspot mixing:A framework for heterodyne mixing in superconducting hot-electron bolometers

We propose a framework to interpret heterodyne mixing in superconducting hot-electron bolometers. The physical conversion process of the mixer is the result of an electronic hotspot, of which the length, and consequently the resistance, oscillates at the intermediate frequency. On the basis of this concept, we calculate the (un)pumped current–voltage relation, the dc voltage responsivity, and the mixer conversion efficiency

Replicating Nanostructures on Silicon by Low Energy Ion Beams

We report on a nanoscale patterning method on Si substrates using self-assembled metal islands and low-energy ion-beam irradiation. The Si nanostructures produced on the Si substrate have a one-to-one correspondence with the self-assembled metal (Ag, Au, Pt) nanoislands initially grown on the substrate. The surface morphology and the structure of the irradiated surface were studied by high-resolution transmission electron microscopy (HRTEM). TEM images of ion-beam irradiated samples show the formation of sawtooth-like structures on Si. Removing metal islands and the ion-beam induced amorphous Si by etching, we obtain a crystalline nanostructure of Si. The smallest structures emit red light when exposed to a UV light. The size of the nanostructures on Si is governed by the size of the self-assembled metal nanoparticles grown on the substrate for this replica nanopatterning. The method can easily be extended for tuning the size of the Si nanostructures by the proper choice of the metal nanoparticles and the ion energy in ion-irradiation. It is suggested that off-normal irradiation can also be used for tuning the size of the nanostructures.Comment: 12 pages, 7 figures, regular paper submitted to Nanotechnolog

Psychosocial work characteristics associated with distress and intention to leave nursing education; a one-year follow-up study

Background: Dropout in later years of the nursing degree programme involves lost investment and is a particular problem for both students and educators. Reasons for late dropout seem to be related to the work and learning environment of the clinical placement. Objectives: The aim of this study was to investigate associations between psychosocial work characteristics and distress and intention to leave nursing education among third-year nursing students. Design: A prospective cohort study. Setting A Bachelor of Nursing programme of a University of Applied Sciences in [name country]. Participants: 363 third-year nursing students. Methods: Baseline and one-year follow-up measurements were used from a prospective cohort study. Third-year nursing students were invited annually in May between 2016 and 2018. Psychosocial work characteristics were psychological demands, supervisor and co-worker support, and acts of offensive behaviour. Logistic regression analyses were used to build multivariate models. Results: Frequent exposure to violence (OR = 2.52, 95% CI: 1.29-4.92) was univariately associated with distress. In the multivariate model for distress, psychological demands (OR = 1.63, 95% CI: 1.05-2.52) and frequent exposure to violence (OR = 3.02, 95% CI: 1.48-6.19) were associated with distress. Supervisor support (OR = 0.54, 95% CI: 0.36-0.80) and co-worker support (OR = 0.41, 95% CI: 0.24-0.72) were negatively associated with intention to leave (i.e. were protective) in the univariate model. In the adjusted multivariate model, only co-worker support (OR = 0.50, 95% CI: 0.25-0.97) was a protective factor for an intention to leave. Conclusion: Psychological demands and frequent exposure to violence are risk factors for distress, and co-worker support is a protective factor reducing the intention to leave nursing education in the last stage of the programme. Improving the psychosocial working climate of nursing students may reduce the intention to leave at a late stage in nursing education, and hence actual late dropout