The Thermodynamic Properties of the f-Elements and their Compounds. Part 2. The Lanthanide and Actinide Oxides

Abstract

A comprehensive review of the thermodynamic properties of the oxide compounds of the lanthanide and actinide elements is presented. The available literature data for the solid, liquid, and gaseous state have been analysed and recommended values are presented. In case experimental data are missing, estimates have been made based on the trends in the two series, which are extensively discussed.

High temperature phase transition of mixed (PuO 2 + ThO 2 ) investigated by laser melting

“…Actinide dioxide melting enthalpy values assessed by Konings et al [29] are used to calculate the optimised solidus and liquidus plotted in figure 7 together with the current experimental data. It is evident that the current experimental data relative to plutonia-rich compositions deviate from such phase diagram.…”

Lanthanide Ionization Energies and the Sub-Shell Break. Part 2. The Third and Fourth Ionization Energies

“…The dioxides of the first three elements have the eight-coordinate fluorite structure. 42 At room temperature, hafnium dioxide has a monoclinic structure in which the hafnium atom is seven-coordinate. However, the cubic fluorite form is stable above 2870 K and there is an experimental value of 5.08 A for its unit cell parameter 51 (internuclear distance 2.20Å).…”

“…Reviews of the enthalpies of formation of lanthanide trichlorides, 40,41 sesquioxides, 42 and aqueous ions 43 give the values shown in …”

“…42 The values of 1/2L Ɵ (Ln 2 O 3 ) can be calculated from columns 4 and 7 of Since this estimate is a constant for each lattice enthalpy, it does not affect the variation, or the subshell break of 38 kJ mol 21 revealed by Fig. 9(C).…”

Melting Point and Thermal Conductivity of UO₂-ZrO₂ Solid Solution: Molecular Dynamics Simulation

“…(2) (NaCl KCl ) calculations, and the blank one was the experimental value recommended for UO2 by Konings [25]. …”