Study of the kinetics of the phase transition of the first order in tetracosane С$_{24}$Н$_{50}$ by Fourier-transform IR spectroscopy

The kinetics of the structural first order phase transition in the tetracosane С$_{24}$Н$_{50}$ monodisperse samples is studied with the help of FTIR spectroscopy. The temperature dependencies of the frequency and intensity of rocking ($\nu$ $\sim$ 720 cm$^{-1}$) and bending ($\nu$ $\sim$ 1470 cm$^{-1}$) vibrations of СН$_2$-groupes in the methylene trans-sequences in the crystalline cores of the elementary lamellae are investigated. It is shown that the first order solid phase transition is developing on a heterogeneous mechanism in the narrow temperature interval ($\Delta T\sim$ 2 K) according to the theory of the diffused first order phase transitions and is due to the crystalline cell symmetry change.