The peculiarities of phase transitions in layered   ferroelectrics-semiconductors $ TlIn_{1-x}Fe_xS_2 $
  The results of differential-thermal analysis of various samples as well as dielectric measurements of solid solutions $TlIn_{1-x}Fe_x^{56,57}S_2$ are presented. It has been established that phase transitions become blurred and shift to low temperatures with increasing the concentration of defects in the layered structure. at some threshold value the structure loses layerity, the crystal becomes isotropig and the distribution of defects does homogeneous. 
R.M.Sardarli, A.P.Abdullayev, O.A.Samedov, N.A.Eubova, B.R.Gadjiyev