The analysis of field evaporation data from field-ion microscope experiments

A method for measuring the field evaporation parameter Q 0 '/ kT is presented, based on the determination of the rate of field evaporation in a field-ion microscope as a function of tip size and tip voltage. For tungsten field evaporated at 87°K a value Q 0 '/ kT = 470 ± 100 was obtained from a series of voltage increment experiments at constant tip size. Field evaporation data can also be combined with field-ion image analysis to give information about the tip shape which is inherently more accurate than can be obtained from field-ion image analysis alone.