Behavior of Ga atoms on a tungsten surface

The variation of the work function and the preexponential term of the Fowler--Nordheim (FN) plots and field emission current from a Ga covered tungsten surface have been studied using a field emission microscope (FEM). The work function and preexponential terms both vary in the same way with coverage and desorption temperature. Both are decreased to 4.25 and -0.6 eV, respectively, at theta = 0.2. In spite of a small decrease in work function, the field emission current decreased to about half of its initial value, because of a decrease in the emitting areas of the Ga covered tungsten surface. The polarizability of Ga, at this coverage, is also obtained as approx.3 A3