Generalized susceptibility of a screw dislocation in ferroelastics near structural phase transition

Small amplitude bending vibrations of a screw dislocation near structural phase transition is considered. Based on the full set of equations describing the vibrations of a crystal with a dislocation near the structural phase transition, written equations for the dynamics of screw dislocations in the linear approximation of the dislocation displacement. Fourier transform of the Peach-Koehler forces projection on the dislocation slip plane is obtained and a linear response function of a screw dislocation in ferroelastic crystal to an external force is found. (paper)