Critical behavior of heat capacity in the vicinity of phase transitions in [NH2(CH3)2]5Cd3Cl11

The heat capacity of a [NH2(CH3)2]5Cd3Cl11 crystal was studied calorimetrically in the temperature interval 100–300 K. The Cp(T) dependence indicates that, as the temperature is lowered, phase transitions occur at temperatures T1 = 176.5 K and T2 = 123.5 K. The thermodynamic characteristics of this crystal were determined. It is shown that the transition at T2 = 123.5 K is an incommensurate-commensurate phase transformation and that the transition at T1 = 176.5 K is a normal-incommensurate phase transition.