Published online by Cambridge University Press: 26 February 2011
High resolution core level photoemission results show the temperature evolution of the V/Ge(111) interface in the range from 300 to 600 K. Three well-defined chemical environments are present for Ge at 300K (the first is the substrate and the other two are reaction products with overall shifts of−0.5 and −0.95 eV). Increasing the temperature enhances Ge outdiffusion, and a homogeneous reacted layer forms when deposition and measurements are done isothermally at 475K. The activation energy for this diffusion process is very low (5 kcal/mole), indicating the importance of grain boundary diffusion at reacting, heterogeneous interfaces.