Evaluation of a Neon Focused Field Ion Source: Fabrication and Characteristics
A new type of gaseous field ion source, operated with the inert gas neon, was developed. The source material used was the equiatomic B 2-ordered Ni-Al alloy doped with small amounts of W and C. Small surface protrusions were formed by the field evaporation of the multiphase alloy containing ultrafine spherical precipitates. The emission current-voltage characteristics were recorded as a function of neon gas pressure and source temperature. Total source current densities of up to 6 nA were obtained. A source temperature just above the condensation point of Ne gas was found to generate the highest ion current
A novel approach to gaseous field ion sources for focused ion beam applications
Abstract Experiments have demonstrated that significantly increased angular current densities may be obtained from protrusions formed from ultrafine precipitates compared to the normal field ion specimens. The confinement of the ion-emitting region to the precipitates is an effective method of increasing the angular current density. This type of emitter may be a potential candidate for gaseous focused ion sources.
Single step formation of biocompatible bimetallic alloy nanoparticles of gold and silver using isonicotinylhydrazide.
Manufacturing nanoparticles with controlled physicochemical properties using environment-friendly routes have potential to open new prospects for a variety of applications. Accordingly, several approaches have been established for manufacturing metal nanoparticles. Many of these approaches entail the use of hazardous chemicals and could be toxic to the environment, and cannot be used readily for biomedical applications. In the present work, we report a single step bio-friendly approach to formulate gold (Au), silver (Ag), and Au-Ag alloy nanoparticles with desired surface corona and composition using isonicotinylhydrazide (INH) as a reducing agent. INH also functioned as a stabilizing agent by enabling a surface corona around the nanoparticles. Remarkably, within a single step INH could also provide a handle in regulating the composition of Au and Ag in bimetallic systems without any additional chemical modification. The physicochemical and surface properties of the different nanoparticles thus obtained have been examined by analytical, spectroscopic and microscopic techniques. Cell cytotoxicity (release of lactate dehydrogenase), cell viability and intracellular reactive oxygen species (ROS) assays confirmed that the Au, Ag, and Au-Ag bimetallic nanoparticles prepared with INH are biocompatible. Finally, the presence of organic surface corona of INH on the nanoparticles was found to impart nanozyme activity and antimycobacterial sensitivity to the nanoparticles.