TY - JOUR
T1 - Thermochemistry of rare earth oxyhydroxides, REOOH (RE = Eu to Lu)
AU - Yang, Shuhao
AU - Powell, Matthew
AU - Kolis, Joseph W.
AU - Navrotsky, Alexandra
N1 - Funding Information:
The calorimetric studies at UC Davis were funded by the U.S. Department of Energy Critical Materials Institute Hub under subaward number SC-18-474. Shuhao Yang would like to thank Tamilarasan Subramani and Novendra for help in calorimetric experiments, and Albert A. Voskanyan for fruitful discussions. The synthesis work was performed at Clemson University and supported by Department of Energy award BES DE-SC0020071 .
PY - 2020/7
Y1 - 2020/7
N2 - As intermediate products of the dehydration of hydroxides or the hydration of oxides, rare earth oxyhydroxides (REOOH) have important implications for synthesis and potential applications in luminescent devices. Using high temperature oxide melt solution calorimetry and thermal analysis, thermodynamic properties of REOOH (RE = Eu to Lu), including enthalpies of dehydration and formation, were determined. The exothermic enthalpies of formation from oxides and endothermic enthalpies of dehydration demonstrate that oxyhydroxides are not only synthetic but also thermodynamic intermediates in rare earth oxide - water systems. The linear relationship between enthalpies of formation from oxides and ionic radius of RE3+ confirms the key role of cation size in the stability of REOOH, and reveals that REOOH with lighter rare earth elements are easier to form and harder to dehydrate, both thermodynamically and kinetically.
AB - As intermediate products of the dehydration of hydroxides or the hydration of oxides, rare earth oxyhydroxides (REOOH) have important implications for synthesis and potential applications in luminescent devices. Using high temperature oxide melt solution calorimetry and thermal analysis, thermodynamic properties of REOOH (RE = Eu to Lu), including enthalpies of dehydration and formation, were determined. The exothermic enthalpies of formation from oxides and endothermic enthalpies of dehydration demonstrate that oxyhydroxides are not only synthetic but also thermodynamic intermediates in rare earth oxide - water systems. The linear relationship between enthalpies of formation from oxides and ionic radius of RE3+ confirms the key role of cation size in the stability of REOOH, and reveals that REOOH with lighter rare earth elements are easier to form and harder to dehydrate, both thermodynamically and kinetically.
KW - Calorimetry
KW - Dehydration enthalpy
KW - Formation enthalpy
KW - Rare earth oxyhydroxide
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U2 - 10.1016/j.jssc.2020.121344
DO - 10.1016/j.jssc.2020.121344
M3 - Article
AN - SCOPUS:85083425650
VL - 287
JO - Journal of Solid State Chemistry
JF - Journal of Solid State Chemistry
SN - 0022-4596
M1 - 121344
ER -