Low-Temperature Heat Capacity and Thermodynamic Functions of Europium(III) Heptafluorodimethyloctanedionate

The heat capacity of europium-(III) heptafluorodimethyloctanedionate (Eu-(C10H10F7O2)(3), IUPAC name: tris-(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato)-europium; CAS number 17631-68-4) was measured by an adiabatic method in a temperature range from 13.47 to 308.44 K. The data obtained were used to calculate thermodynamic functions (entropy, enthalpy, and reduced Gibbs energy) at temperatures ranging from 0 to 310 K. The heat capacity behavior analysis found two lambda-anomalies in the range of 123 to 220 K, which indicated two second-order transitions in this temperature range.