The early stage of formation of self-organized nanocolumns in thin films: Monte Carlo simulations versus atomic-scale observations in Ge-Mn

International audienceFormation kinetics of self-organized nanocolumns during epitaxial growth of a thin film composed of immiscible elements (A,B) has been investigated using Kinetic Monte Carlo simulations. Simulated nanostructures show a good agreement with those observed in Ge-Mn using Atom Probe Tomography and Transmission Electron Microscopy. Self organisation is observed although the rigid lattice simulations used do not account for misfit elastic strain. Simulations reveal that the final nanostructure, in term of number density and diameter of nanocolumns, is controlled by the early stages of growth of the film. The influence of both growth temperature and solute concentration on the nanostructure features is discussed in details. V C 2014 AIP Publishing LLC

The early stage of formation of self-organized nanocolumns in thin films: Monte Carlo simulations versus atomic-scale observations in Ge-Mn

International audienceFormation kinetics of self-organized nanocolumns during epitaxial growth of a thin film composed of immiscible elements (A,B) has been investigated using Kinetic Monte Carlo simulations. Simulated nanostructures show a good agreement with those observed in Ge-Mn using Atom Probe Tomography and Transmission Electron Microscopy. Self organisation is observed although the rigid lattice simulations used do not account for misfit elastic strain. Simulations reveal that the final nanostructure, in term of number density and diameter of nanocolumns, is controlled by the early stages of growth of the film. The influence of both growth temperature and solute concentration on the nanostructure features is discussed in details. V C 2014 AIP Publishing LLC

Bacterial isolates and factors associated with infection and outcome in calves with septic arthritis

Lameness is an important problem in cattle and is often associated with an important economic loss in beef and milk production. Because of the pain, it is becoming an important welfare issue and represents 1 of the major culling causes in dairy herds. The joint is the second most important cause of lameness after the digit.&#x0D; There is in an important lack in the literature regarding prognosis and factors associated with septic arthritis in calves. The objective of the study is to determine clinical characteristics, clinicopathologic data, and bacterial culture results associated with septic arthritis in calves less than 180 days old and to establish long-term prognosis of the condition.</jats:p

Retrospective study of retroperitoneal abscess in cattle

A retroperitoneal abscess is a collection of suppurative fluid between the peritoneum, the transverse and internal oblique muscles. It was reported in cattle following laparotomy. The objectives of this retrospective cases-series study are to describe the clinical signs, clinical pathological findings, treatment options and outcome.</jats:p

Growth rate model and doping metrology by atom probe tomography in silicon nanowire

Silicon nanowires (SiNWs) with different surface number density are fabricated using Chemical Vapor Deposition (CVD) method by controlling the catalyst droplet number density with in-situ evaporation. For comparison, another type of SiNWs is fabricated by Molecular Beam Epitaxy (MBE) method. To study these two types of SiNWs a general growth rate model is presented. The fit curves from this model are consistent with our experimental data. In both growing conditions the SiNW growth rate as a function of their diameter are compared and discussed. The p-type SiNWs have also been prepared by adding diborane into precursor. The doping metrology in an individual SiNW is realized by laser assisted Atom Probe Tomography (APT). We have shown that the doping atoms (e.g. B) can incorporate into SiNW and an accurate quantification can be given

Study of the effect of gas pressure and catalyst droplets number density on silicon nanowires growth, tapering, and gold coverage

We investigated the growth of silicon nanowires from Au-rich catalyst droplets by two different methods: chemical vapor deposition (CVD) and molecular beam epitaxy (MBE). The growth rate is found to be diameter-dependent and increases with increasing precursor partial pressures. The comparison of the experimental results with models shows that the contribution of Si atoms that diffuses from the substrate and the NW sidewalls toward the catalyst droplet can be neglected in CVD for the different pressures used in this study, whereas it is the major source of Si supply for the MBE growth. In addition, by decreasing the number density of catalyst droplet prior to the NW growth in CVD, it is also found that this parameter affects the NWs morphology, increasing the tapering effect when the silane partial pressure is small enough to allow gold atom diffusion from the catalyst drople