Dust-acoustic solitary wave in finite temperature dusty plasma with variable dust charge and two temperature ions

Recently considerable research interests have been witnessed in large amplitude coherent nonlinear wave structures. Particularly, collective effects involving highly charged grains in dusty plasmas with constant as well as variable grain charge have been studied. However, the finite dust temperature can not be ignored. A full characteristics of dust-acoustic solitary wave is possible if dust charge and temperature are considered as variable. Instead of deriving KdV or MKdV equations using reductive perturbation method, we have used here Sagdeev pseudopotential method to investigate the possibility of compressive as well as refractive solitons. An expression for pseudopotential, which is a function of Mach number, relative temperature of low and high ion components, relative ion concentration, dust charge and temperature. Numerical computation shows that for chosen set of parameters, only compressive solitons exist and their amplitude increase with increase in Mach number. Increase in dust temperature leads to disappearance of the compressive soliton. However, increase in Mach number results in re-emergence of the disappeared soliton. It is only small parameter regime for which both, compressive as well as refractive solitons coexist. Effect of relative ion temperature on solitons is also investigated. Thus, on using Sagdeev pseudopotential, it is possible to investigate soliton over a wide range of parameter space. Variable dust charge and temperature, further add a new scenario to the soliton dynamics of multi-species plasmas.