Vaporization thermodynamics of lanthanide trihalides

Abstract

Published data on the vaporization of the lanthanide trihalides have been reviewed, and enthalpies of sublimation at 298.15 K have been calculated by the secondand third-law methods using thermodynamic functions for gaseous and condensed states developed in an internally consistent manner. Preferred values of the third-law enthalpies were selected, primarily on the basis of agreement between the secondand third-law results. The selected values for the fluorides and chlorides show variations from a smooth trend across the lanthanide series greater than would be expected from experimental uncertainties, while the results for the bromides and iodides exhibit relatively smooth behavior.There has been considerable recent interest in the vaporization behavior and thermodynamics of the lanthanide trihalides; over 20 studies have been reported in the past 15 years. Most Sml3 to Lul3 (5). For each structure type, a plot of Hm vs. 7m is essentially linear, and, using the melting points given by Brown (5), enthalpies of fusion are estimated to be (kcal/mol) the fol-

Giant onsite electronic entropy enhances the performance of ceria for water splitting

“…Myers et al 38 extracted the electronic entropy contribution of lanthanide ions (Ln 3+ ) in lanthanide trihalides from absolute entropy data. Our calculated electronic entropies per ion at ≈300 K in units of k B compared with Myers et al 38 data (value inside parentheses) are the following: Ce 3+ , 1.79 (1.77); Pr 3+ , 2.19 (2.18), Nd 3+ , 2.30 (2.27); Eu 3+ , 1.13 (1.10); Tb 3+ , 2.56 (2.54). The calculated based on L – S coupling shows excellent agreement with previously reported data.…”

Recent Progress and Approaches on Carbon-Free Energy from Water Splitting

“…Myers and Graves [ 104 ] took out the electronic entropy involvement from absolute entropy data of lanthanide (Ln 3+ ) ions in lanthanide trihalides, which are comparable with the new approach of Naghavi et al [ 103 ]. Having the energy and degeneracy ( ) of each microstate, of a system with m different microstates was calculated by the following equation, where is the probability of thermal excitation and Z is the partition function.…”

Mass spectrometric investigation of neutral and charged constituents in saturated vapor over PrI3

“…In contrast to lanthanide trichlorides (e.g., [4][5][6]), thermodynamic information on gaseous species of lanthanide triiodides is scanty; only monomer molecules was reported [7] whereas the information on dimer molecules and ionic species is lacking practically.…”