Heat transfer in area of ferroelectric phase transitions

By measuring thermal conductivity and thermal diffusivity in the vicinity of ferroelectric phase transitions, the processes of polar bonds self-ordering and its forced-ordering by bias electrical field are studied. Thermal energy transfer in polar crystals is inhibited, since responsible for heat transfer shortwave acoustic phonons interact with optical phonons. But in the antiferroelectrics, it is found that optical-acoustic interaction may reinforce thermal diffusion, which is expressed as a large sharp maximum of diffusivity, because soft phonon frequency vanishes in the middle of Brillouin zone that promotes optical phonons participation in heat transfer together with acoustic phonons.