Compressive and rarefactive dust-ion acoustic solitary waves in four components ‎quantum plasma with dust-charge variation

Based on quantum hydrodynamics theory (QHD), the propagation of nonlinear quantum dust-ion acoustic (QDIA) solitary waves in a ‎collision-less, unmagnetized four component quantum plasma consisting of electrons, positrons, ions and stationary negatively charged ‎dust grains with dust charge variation is investigated using reductive perturbation method. The charging current to the dust grains carried ‎by the plasma particle, has been calculated with the orbit-limited motion approach. The quantum current of electrons and positrons is ‎obtained by using Fermi-distribution functions. The basic features of QDIA solitary waves are studied by deriving the Korteweg-de Vries ‎‎(KdV) Equation. It is found that both rarefactive and compressive type of solitons can exist in the model plasma. Further, the nonlinear ‎and dispersive coefficients in KdV equation are modified by consideration dust charge variation effect and Fermi-Dirac distribution ‎function. The present investigations should be useful for researches on astrophysical plasmas as well as for ultra small micro- and nano- ‎electronic devices.‎