Structural and Thermodynamic Investigation of the Perovskite Ba₂NaMoO_5.5

Neutron diffraction, X-ray absorption spectroscopy (XAS), and Raman spectroscopy measurements of the quaternary perovskite phase Ba₂NaMoO_5.5 have been performed in this work. The cubic crystal structure in space group Fm3¯ m has been refined using the Rietveld method. X-ray absorption near-edge structure...

Investigation of the Cs₂(Mo,Te)O₄Solid Solution and Implications on the Joint Oxyde-Gaine System in Fast Neutron Reactors

The formation of a thin layer, the so-called Joint Oxyde-Gaine (JOG), between the (U,Pu)O2 fuel pellets and the cladding has been observed in fast neutron reactors, due to the accumulation of volatile fission products. Cs2MoO4 is known to be one of the major components of the JOG, but other elements are also present, in particular tellurium...

In situ high-temperature EXAFS measurements on radioactive and air-sensitive molten salt materials

The development at the Delft University of Technology (TU Delft, The Netherlands) of an experimental set-up dedicated to high-temperature in situ EXAFS measurements of radioactive, air-sensitive and corrosive fluoride salts is reported. A detailed description of the sample containment cell, of the furnace design, and of the measurement...

Hygroscopic properties of potassium-halide nanoparticles

The hygroscopic properties of KBr, KCl, and KI nanoparticles having diameters from 8 to 60 nm were measured using a tandem Differential Mobility Analyzer. In all cases, the deliquescence and efflorescence relative humidity values increased with decreasing particle diameter. The associated growth factors also decreased with decreasing particle...

A New Look at the Structural and Magnetic Properties of Potassium Neptunate K₂NpO₄ Combining XRD, XANES Spectroscopy, and Low-Temperature Heat Capacity

The physicochemical properties of the potassium neptunate K₂NpO₄ have been investigated in this work using X-ray diffraction, X-ray absorption near edge structure (XANES) spectroscopy at the Np-L₃ edge, and low-temperature heat capacity measurements. A Rietveld refinement of the crystal structure is reported...

Structural Properties and Charge Distribution of the Sodium Uranium, Neptunium, and Plutonium Ternary Oxides: A Combined X-ray Diffraction and XANES Study

The charge distributions in α-Na₂UO₄, Na₃NpO₄, α-Na₂NpO₄, Na₄NpO₅, Na₅NpO₆, Na₂PuO₃, Na₄PuO₅, and Na₅PuO₆ are investigated in this work using X-ray absorption near-edge...

Crystal-Field and Covalency Effects in Uranates: An X-ray Spectroscopic Study

The electronic structure of U^V- and U^VI-containing uranates NaUO₃and Pb₃UO₆was studied by using an advanced technique, namely X-ray absorption spectroscopy (XAS) in high-energy-resolution fluorescence-detection (HERFD) mode. Due to a significant reduction in core–hole lifetime broadening,...