Containerless fabrication of tungsten single crystals using laser CVD for field emission applications

Single crystalline tungsten rods have been grown by a containerless technique in a cold atmosphere. The technique used was thermal laser assisted chemical vapour deposition (LCVD), and the crystals were grown from a reaction gas mixture of WF6 and H-2. Both separate crystals and array configurations have been made. The field emission characteristics for the separate tungsten single crystals have been evaluated, and the cathode radii in the order of 80 nm were obtained from the Fowler-Nordheim plot.