The kinetics of the α-β phase transition of HgI2 were investigated by isothermal and non-isothermal differential scanning calorimetry. The effective activation energy of
the transition, 41540 kJ mol-1, was determined applying the methods of Kissinger and Ozawa. The transition kinetics were described by the Johnson-Mehl-Avrami
model and the value of the Avrami exponent n was found to range from high values (n>3) at the early stages to lower values at later stages of the transformation, with an average value of 2.