Study of the phase transition and thermodynamic functions of LiMn2O4

Abstract The temperature dependence of heat capacity of LiMn 2 O 4 has been measured for the first time in the range from 6 to 347 K by precision adiabatic vacuum calorimetry. The experimental data were used to calculate standard thermodynamic functions, namely the heat capacity, enthalpy H ° ( T ) − H° (0), entropy S ° ( T ) −  S ° (0) and Gibbs function G ° ( T ) − H° (0), for the range from T  → 0 to 347 K. The low-temperature and high-temperature X-ray diffraction were used for the determination of type and temperature of phase transitions and coefficients of thermal expansion. Additional spectroscopic studies were carried out to study the nature of the phase transition from an orthorhombic to cubic phase at 286 K.