Deviation from the mean field theory in the critical behavior of ferroelectric TGSe

Abstract
The deviation from the mean field theory in values of the ratios X(O, TM)/X(E, TM ) for TGSe was found, where X(E, TM ) is the value of the maximum in the temperature dependence of electric susceptibility in a non-zero electric field parallel to the measuring field, X(O, TM ) is the initial susceptibility of the same temperature TM . It is stressed that not only the quality of the sample (imperfections and non-homogenities) but also other mechanisms are responsible for this deviation.