Coverage dependence of field emission flicker noise due to lithium adsorbed on the W(112) surface

Spectral density functions of field emission current fluctuations were investigated by a probe hole technique for lithium adsorbates on the tungsten (112) surface plane in the sub- to double monolayer range. The dependence of the spectral density on the lithium surface concentration obtained slightly above room temperature, shows maxima and minima. A correspondence is found between the extrema of the coverage dependent spectral density, features of the work function, and the film structures occurring with different adparticle densities. Commensurate lithium structures are clearly manifest in the noise power.