Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Low-temperature structural phase transition in deuterated and protonated lithium acetate dihydrate

Schroder, F., Winkler, B., Haussuhl, E., Cong, P. T., Wolf, B., Avalos-Borja, M., Quilichini, M., Hennion, B.
J. Chem. Thermodyn. 2010, 42, 8, 957-961
ABSTRACT
Heat capacity measurements of protonated lithium acetate dihydrate show a structural phase transition at T = 12 K. This finding is in contrast to earlier work, where it was thought that only the deuterated compound undergoes a low temperature structural phase transition. This finding is confirmed by low temperature ultrasound spectroscopy, where the structural phase transition is associated with a velocity decrease of the ultrasonic waves, i.e. with an elastic softening. We compare the thermodynamic properties of the protonated and deuterated compounds and discuss two alternatives for the mechanism of the phase transition based on the thermal expansion measurements.
Compounds
# Formula Name
1 C2H7LiO4 lithium ethanoate dihydrate
2 C2D7LiO4 lithium acetate-d3 di(hydrate-d2)
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • Triple point temperature, K ; Crystal 2
  • Crystal 2
  • Crystal 1
  • Gas
  • Quantum Design PPSM 6000
  • 1
  • POMD
  • 1
  • Molar heat capacity at constant pressure, J/K/mol ; Crystal 2
  • Temperature, K; Crystal 2
  • Pressure, kPa; Crystal 2
  • Crystal 2
  • Quantum Design PPSM 6000
  • 4
  • POMD
  • 1
  • Molar heat capacity at constant pressure, J/K/mol ; Crystal 1
  • Temperature, K; Crystal 1
  • Pressure, kPa; Crystal 1
  • Crystal 1
  • Quantum Design PPSM 6000
  • 10
  • POMD
  • 2
  • Triple point temperature, K ; Crystal 2
  • Crystal 2
  • Crystal 1
  • Gas
  • Quantum Design PPSM 6000
  • 1
  • POMD
  • 2
  • Molar heat capacity at constant pressure, J/K/mol ; Crystal 2
  • Temperature, K; Crystal 2
  • Pressure, kPa; Crystal 2
  • Crystal 2
  • Quantum Design PPSM 6000
  • 7
  • POMD
  • 2
  • Molar heat capacity at constant pressure, J/K/mol ; Crystal
  • Temperature, K; Crystal
  • Pressure, kPa; Crystal
  • Crystal
  • Quantum Design PPSM 6000
  • 6