The structure and occurrence of the metastable monoclinic phase, α′b, in uranium-molybdenum alloys

Characterization of cubic γ-phase uranium molybdenum alloys synthesized by ultrafast cooling

“…Such a splitting is considered as an evidence of an increase of the c-angle between the a-and b-axis (c-angle > 90°) [8] and a formation of a a 00 b phase. The lower limit of detection of the a 00 b phase was found at 5.9 at.% Mo [13] in the water-quenched alloys (from T = 1113 K), while the upper limit was estimated to be 11.18 at.% Mo [8] with c-angles = 90.25°and 93.5°, respectively. In the current work, whilst no splitting (of the a-uranium reflections) was observed in the XRD spectra for low Mo concentrations (<10 at.%), a large broadening was observed for all a-reflections.…”

Straightforward understanding of the structures of metastable α″ and possible ordered phases in uranium–niobium alloys from crystallographic simulation

“…2 was mistakenly used for the input model during structure refinement for a 00 phase in Ref. [14]. Therefore, the internal stress should be eliminated due to its disturbance in experimental observation and subsequent data analysis.…”

“…2 corresponds to the triclinic structure but not to the monoclinic one, where the two angles a and b are set purposely to be 90 , as used by Ref. [14] for structure analysis. Fig.…”

“…For this reason, the analysis on structure of a 00 phase is usually performed in an indirect or incorrect way. For example, in a current and early work [13,14], diffraction pattern of a 00 phase is indexed by the orthorhombic and triclinic a lattice, respectively.…”

Neutron and hard X-ray diffraction studies of the isothermal transformation kinetics in the research reactor fuel candidate U–8 wt%Mo

“…An enrichment in Mo leads to a distortion of the lattice and hence the formation of the phases 0 -U and 00 -U (Lehmann & Hills, 1960;Orlov & Teplinskaya, 1999;Stewart & Williams, 1966). Owing to the inclusion of carbide and nitride during the production process of the material by the AREVA-CERCA company, one other phase was added.…”