Field-emission properties of ultrathin 5 nm tungsten nanowire

We report the field-emission properties of ultrathin tungsten nanowires of 5 nm diameter and several hundred nanometer length. Fowler-Nordheim plots of field-emission current-voltage measurements of such nanowires show marked deviation from linearity. After flashing, cold-field-emission current stability with standard deviation of better than 1% has been observed for periods of at least 30 min at a vacuum level of 10(-9) mbar. Beyond this, field-emission current noise was found to mainly comprise current step jumps and current spikes. At high emission current densities in the order of 10(6) A cm(-2), the noise changes into flicker noise. Field emission at high current density induced surface diffusion and crystallization of the disordered nanowire tip due to temperature rise at the field-emitting tip. Further increase in the emission current density initiated local arc destruction which caused shortening of the nanowire length. (c) 2006 American Institute of Physics.