On the Use of Chromium Coating for Inner-Side Fuel Cladding Protection: Thickness Identification Based on Fission Fragments Implantation and Damage Profile

Inner-side coatings have been proposed as a complementary solution within the accident tolerant fuel (ATF) framework, to provide enhanced protection for the nuclear fuel cladding. Unlike external surface, the degradation of irradiated internal cladding surface has not been studied extensively. Fission fragments produced during the fission of nuclear fuel is one of the key players in this degradation. This study aimed to estimate the minimum thickness of the thin chromium film, required to protect the inner side of the nuclear fuel cladding. The approach used is based on a set of calculations, of Ion ranges and damage profiles, for a group fission fragments, using the TRIM code. The calculation results were verified by comparison with the experimental data associated with the phenomena of the inner cladding degradation of thermo-releasing elements. The recommended minimum thickness for such a film was found to be 9 microns. Calculations also showed that chromium metal has a greater stopping power compared to the zirconium-based alloy E110, which indicates an increased ability of chromium to withstand exposure to energetic fission fragments during reactor operation.

Evidence of a magnetic transition in atomically thin Cr2TiC2Tx MXene

Evidence for a magnetic transition in atomically thin chromium titanium carbide MXene (Cr2TiC2Tx) has been shown experimentally using a combination of magnetometry, spectroscopy, and magnetotransport measurements.

Impact of substrates on the electrical properties of thin chromium films [Online First]

Objective: We studied the impact of substrates on the electrical properties of thin chromium films. Substrates may serve many purposes, such as to define orientation, to conduct electrical current in vertical devices, as a gate in transistors, etc. The thickness range of the chromium films grown on both substrates was (3.5-70) nm. Methods and materials: We used Fuchs-Sondheimer(FS) and Mayadas-Shatzkes(MS) theories to analyze electrical resistivity data for chromium(Cr) films grown on both substrates simultaneously by thermal evaporation in vacuum, under identical deposition conditions. Results and discussion: The infinitely thick film resistivity (ρ0), conduction electron mean free path(l), specularity parameter(p), scattering power of the grain boundary(α') and grain boundary reflection coefficient(R') were found to depend upon the nature of the substrate and the binding force between them and evaporated chromium atoms. The growth and microstructure of the chromium films were examined using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Conclusions: Our experimental data exactly fits with the MS theory in the entire thickness range grown for the chromium films deposited on both the substrates. Examination of film structure by SEM indicated that the films consist of grains of relatively pure chromium of different sizes, and depends upon deposition conditions and parameters, which are important factors that dictate the structural properties of the films.

Evolution of interlayer and intralayer magnetism in three atomically thin chromium trihalides

We conduct a comprehensive study of three different magnetic semiconductors, CrI3, CrBr3, and CrCl3, by incorporating both few-layer and bilayer samples in van der Waals tunnel junctions. We find that the interlayer magnetic ordering, exchange gap, magnetic anisotropy, and magnon excitations evolve systematically with changing halogen atom. By fitting to a spin wave theory that accounts for nearest-neighbor exchange interactions, we are able to further determine a simple spin Hamiltonian describing all three systems. These results extend the 2D magnetism platform to Ising, Heisenberg, and XY spin classes in a single material family. Using magneto-optical measurements, we additionally demonstrate that ferromagnetism can be stabilized down to monolayer in more isotropic CrBr3, with transition temperature still close to that of the bulk.