Nucleation studies in supersaturated aqueous solutions of urea and thiourea doped with inorganic dopants

Induction periods were measured for various supersaturated aqueous solution s of urea doped separately with NH4NO3 and NaNO3 and thiourea doped separat ely with NaCl and KCl by the direct vision method. Based on classical theor y for homogeneous crystal nucleation various critical nucleation parameters were calculated and the results are reported and discussed. In all the cas es, the critical nucleation parameters increased with increase in doping co ncentration.