Field Desorption by Alternating Fields. An Improved Technique for Field Emission Microscopy

Abstract

The inclusion of field desorption in field emission microscopy yields additional information on adsorption systems and easily produces clean surfaces of metal tips without the application of heat. An alternating field technique is described using a dc‐biased ac power supply for providing the desorption field during the positive portion of the cycle and allowing the observation of the field electron image during the negative portion. Ion and electron current during one cycle are calculated for a tungsten tip. Patterns from clean nickel, iron, and copper are shown.