Field emission from a nickel adsorbed tungsten tip: Temperature dependent growth and its effects on current stability

Field electron emission from nickel adsorbed tungsten tip has been studied. The effect of equilibration temperature on the growth pattern of nickel overlayers has been investigated. Nickel doses have been equilibrated, in two separate sets of experiments at 760 and 960 K. Corresponding to these two cases the variations in the work function and the pre-exponential term with nickel coverage have been obtained using ten-point Fowler–Nordheim (F–N) plots and distinguishable growth features have also been observed in their respective field emission patterns. The field emission current-time characteristics have been recorded in the two cases. The emission current has been found to be remarkably stable for the case when nickel doses on tungsten tip have been equilibrated at higher temperature of 960 K. This stability in the field emission current has been attributed to almost negligible damage by ion bombardment on the hard and chemically stable nickel-adsorbed tungsten tip surface. The results have been discussed in the light of the existing literature.