We report the dependence of the radius of the encapsulated nanoparticles, the inner metal nucleus and the thickness of the a-C encapsulant layer on the argon gas pressure and the diameter of the silver electrode in the high-current pulsed arc synthesis technique. The deposits were studied by XRD, TEM, SEM and EDX. The radius of the nanoparticles varied from ~55 to 9 nm as the Argon pressure was decreased from 106 to 13 kPa, at 66 kPa the radius of the nanoparticle and nucleus decreased from 34 to 11 nm and 19 to 9 nm, respectively, as the cross-sectional area of the silver electrode was increased from 0.13 to 1.13 x 10-6m2.