By step fluctuation experiments on V(011) thin films grown on (11▪0) α-Al2O3, using low-energy electron microscopy, the coefficient of surface mass diffusion, Ds, was determined at 1170 to 1560K (centered on 0.6Tm), with a melting point of 2183K for V. As was common to annealed V, Nb and Ta in UHV, sub-monolayer coverages of O were present on the otherwise clean and well-defined surface. The relationship, was found for this temperature interval (figure 5). Compared to Nb(011), the step stiffness obtained from the measurements was relatively small and isotropic at ~60meV/nm. Sublimation was made visible by up-hill step flow above 1460K, with a temperature dependence consistent with the known cohesive energy.

Surface Mass Diffusion and Step Stiffness on V(011). M.Ondrejcek, M.Rajappan, W.Swiech, C.P.Flynn: Journal of Applied Physics, 2006, 100[8], 083523 (6pp)

Figure 5

Diffusivity of V on V Surfaces