  The propagation of small amplitude stationary profile nonlinear solitary
waves in a pair plasma is investigated employing the reductive perturbation
technique via well-known Korteweg de Vries (KdV) and modified KdV (mKdV)
equations, we tend to derive the exact form of nonlinear solutions, and study
their characteristics. Two distinct pair ion species are considered of opposite
polarity and same mass, additionally to a massive charged background species,
that is assumed to be stationary, given the frequency scale of interest within
the pair ion context, the third species is thought of as a background defect
(e.g. charged dust) component. On the opposite hand, the model conjointly
applies formally to electron positron ion (epi) plasmas, if one neglects
electron positron annihilation. A parametric analysis is carried out, as
regards the impact of the dusty plasma composition (background number density),
species temperature(s) and background species. It is seen that distinguishable
solitary profiles are observed for KdV and mKdV equations. The results are of
connection in pair ion (fullerene) experiments and additionally potentially in
astrophysical environments, e.g. in pulsars.
