A new crucible design of the arc-discharge method for the synthesis of graphite encapsulated metal (GEM) nanoparticles

► The new crucible setup improved the synthesis of GEM nanoparticles. ► Thermal gradient controlling is the key to the success of this new design. ► It is feasible to change the thermal gradient in the crucible by a ceramic piece. ► Other thermal sensitive systems may benefit from the results of this study.