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• Uranium and cerium containing samples were examined as part of an international nuclear forensics exercise. • The main technique for characterization was the combined analysis by SEM-EDS/Raman of the surface. • Connection between the ingots was determined by uranium and cerium isotopic ratios as well as yttria and graphite surface contaminations. • Sample preparation history was interpreted based on surface contaminations, showing multiple impurities present in suggested production and processing sites. The objective of this paper is to describe nuclear forensics material characterization, as conducted in the Israeli National Nuclear Forensic Laboratory (INNFL) during an international exercise Collaborative Material Exercise 6 (CMX6) organized by the Nuclear Forensics international technical working group (ITWG). The characterized materials are uranium and cerium metal ingots. The goal was characterization of physical parameters, elemental and isotopic composition, morphology and chemical composition of the surface. Electron microscopy and Raman spectroscopy techniques were combined for morphological, structural and elemental study of the surface. The information from these analyses was used to answer the exercise questions, comparing the materials (labeled ES-1 and ES-2) to each other and to other samples described in the scenario. The INNFL investigation identified a connection between ES-1 and ES-2 based on several indicators, including the isotopic composition of the uranium present in both samples, as well as other surface contaminations, mainly yttria and graphite. Based on these finding the INNFL established a connection between ES-1 and ES-2 to ES-3B (theoretical sample with uranium traces) and has not established a connection to ES-3A (theoretical sample of plutonium powder). ES1 and ES-2 have been suggestively connected to their theoretical source, by their isotopic ratio. The INNFL conclusion was that the theoretical source materials (oxide and fluoride) were converted into the actual materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Anode materials for Li-ion batteries based on a conversion mechanism show very high theoretical specific capacities. In particular, phosphide materials display volumetric and gravimetric capacities far beyond graphite, approaching those of silicon-based materials. However, the slow kinetics and large mechanical strain during the conversion process are challenging issues toward enabling phosphide-based anode materials. Here, we synthesize a copper phosphide free-standing membrane and show the benefits of this approach, which provides lighter electrodes with faster kinetics during lithiation and delithiation. The Cu 3 P membrane is both binder-free and carbon black-free, and its synthetic process involves a simple chemical vapor deposition of phosphorus on a composite polymer-copper membrane at a moderate temperature of 429 °C. Microscopic and other methods show the purity of the phase and of the porous structure within the membrane. Galvanostatic cycling reveals an initial discharge reaching the theoretical capacity, high reversible capacity of 320 mAh/g electrode (including the current collector), and good kinetics for phosphide-based materials at C/5 rate. [ABSTRACT FROM AUTHOR]