Field ionization of argon using β-phase W nanorods

We report testing of beta-phase W nanorods as a gas ionizer for neutral argon atoms. These W nanorods having square-base pyramidal apexes were grown on oxidized Si(100) substrate using glancing angle sputter deposition technique with substrate rotation. Only a few volts of positive anode voltage (3-4 V) applied to the W nanorods generates a high electric field, which ionizes gas-phase argon atoms and generates ion currents up to several tenths of microamperes. The low anode voltage and high ion current observed in this study indicates that beta-phase W nanorods can be used as battery-operated gas ionizers. (C) 2004 American Institute of Physics.