Localized electrostatic excitations in e-p-i plasmas and fullerene pair ion plasma doped with dust defects

Nonlinear pulse propagation is considered in a three-component plasma, consisting of warm electron-positron pair species (or fullerene ions) and a stationary heavy ion species (or dust particulates). The basic set of fluid equations is reduced to a Korteweg-de Vries (KdV) equation, by using a reductive perturbation method. It is shown that behavior of the amplitude and the width of small amplitude nonlinear electrostatic waves depends strongly on beta and sigma. It is pointed out that the nonlinearity term does not vanish for any certain parameter values, so that solitons of the modified KdV type are irrelevant in this plasma system.