AVS 47th International Symposium
    Surface Science Tuesday Sessions
       Session SS1-TuM

Paper SS1-TuM3
Reactive Scattering Studies of Organophosphorous Compounds on Semiconducting Metal Oxides

Tuesday, October 3, 2000, 9:00 am, Room 208

Session: Reactions on Oxides and Environmental Chemistry
Presenter: B.G. Frederick, University of Maine
Authors: J.L. Duncan, University of Maine
S. Ma, University of Maine
R.H. Jackson, University of Maine
B.G. Frederick, University of Maine
Correspondent: Click to Email
Semiconducting metal oxides (SMOs) are promising materials for the development of conductivity-based chemical sensors with a broad range of applications. The reactions of organophosphorous compounds are of interest for detection of pesticides and nerve agents. Improvement of the selectivity of SMO sensors requires an understanding of the steps in the decomposition or reaction mechanism which lead to changes in conductivity. We present results of reactive, molecular beam scattering studies for dimethyl methyl phosphonate (DMMP), and related compounds from tungsten oxide based sensors. The experiments utilize molecular beam doser sources with known flux distributions and a differentially-pumped, calibrated mass spectrometer system allowing the coverage, sticking coefficients, and reactive scattering probabilities to be quantified. Reactive scattering of methanol, formic acid, trimethyl phosphine oxide, and trimethyl phosphonate, contribute to understanding the decomposition mechanism of DMMP and the associated conductivity changes observed in the SMO films.