Photoinduced nematic-isotropic phase transition: A case for the random-field Ising model - art. no. 041702

Experiments have been carried out on a photoactive guest-nonphotoactive hos t system exhibiting a photoinduced nematic-isotropic phase transition. It i s shown that the phenomenon of photoinduced shift in the transition tempera ture is similar to the induction of cooperative chiral order in "sergeant-s oldier" copolymer systems. An expression resembling the one given by the ra ndom-field model proposed for the latter system is seen to quantitatively d escribe the shift in the transition temperature as a function of the magnit ude of the radiation.