Entropies of phase transitions in the M3LnCl6 compounds (MK, Rb, Cs; LnLa, Ce, Pr, Nd) and K2LaCl5

摘要: Abstract The molar enthalpies of the solid-solid and solid-liquid phase transitions were determined by differential scanning calorimetry for compounds K2LaCl5, Rb3LaCl6, Cs3LaCl6, K3CeCl6, Rb3CeCl6, Cs3CeCl6, K3PrCl6, Rb3PrCl6, Cs3PrCl6, K3NdCl6, Rb3NdCl6 Cs3NdCl6. K3LnCl6 (LnCe, Pr, Nd) Rb3LaCl6 compounds, which do not exist at room temperature, are formed high temperature with a considerable loss enthalpy (48–55 kJ mol−1) compensated gain in entropy (63–65 J mol−1 K−1). Cs3LnCl6 (LnLa, Ce, stable ambient temperature; they undergo transition solid state corresponding 7.4–7.8 10.9–11.2 K−1. calorimetric measurements show that Rb3PrCl6 also probably temperature. entropies fusion reported all mentioned above.