Modulated Surface-Plasmon Resonance forIn SituMetal-Film Surface Studies

A new experimental technique, angle-of-incidence modulated surface plasmon resonance, is used for in situ studies on noble-metal films. The method is used to record the real and imaginary parts of the surface-plasmon wave vector and the strength of the surface roughness scattering during room-temperature ${\mathrm{O}}_2$ exposure. The atomic susceptibility of oxygen on Cu at 632.8 nm is found to be ${\chi }_a=(1.2+1.6i)\mathrm{}\times {10}^{-24\mathrm{}}$ ${\mathrm{cm}}^3$. Roughly 0.2% of a monolayer can be detected.