Abstract
We report a new method for studying surface reactions and kinetics at moderately high pressures () in near real time. A cylindrical substrate in a reactor wall is rotated at up to 200 000 rpm, allowing the surface to be periodically exposed to a reactive environment and then analyzed by a triple-differentially pumped mass spectrometer in as little as thereafter. We used this method to study oxygen plasma reactions on anodized aluminum. When the substrate is spun with the plasma on, a large increase in signal at is observed with increasing rotation frequency, due to O atoms that impinge and stick on the surface when it is in the plasma, and then recombine over the to 40 ms period probed by changing the rotation frequency. Simulations of signal versus rotation frequency indicate a wide range of recombination rate constants, ascribed to a range of O-binding energies.
- Received 18 July 2005
DOI:https://doi.org/10.1103/PhysRevLett.96.018306
©2006 American Physical Society