Abstract
Nonlinear properties of dust-ion acoustic freak waves have been studied in homogeneous unmagnetized dusty plasmas consisting of ions, nonthermal fast electrons, and positive and negative dust grains. By using derivative expansion method under the assumption of strongly dispersive medium, the basic equations are reduced to nonlinear Schrodinger equation (NLSE). One of NLSE solutions in the unstable region is the rational one which is responsible for creation of the freak waves. The dependence of the freak wave profile on the dust grain charge, carrier wavenumber, and energetic nonthermal electron population is discussed.