Surface density of states on the (0001) face of titanium

Abstract

A titanium microcrystal has been grown by the evaporation of titanium onto a tungsten field emitter. The titanium surface was kept clean by maintaining a residual gas pressure of 10−9 Pa in the vacuum chamber. The surface density of states on the (0001) face of titanium was determined by the photofield emission method using photon energies hν=1.963, 2.409, 2.497, 2.541 and 2.602eV. The full-potential linearized augmented plane wave method was used to calculate the surface density of electron states of Ti(0001). It is concluded that the photocurrent is dominated by photofield emission from a surface state which lies just below the Fermi energy, and that fine structure in the photocurrent is due to modulation of the density of final states by a set of narrowly spaced surface resonances.