Diode laser spectroscopy of adsorbed gas on metal surfaces.
Electroreflectance vibrational spectroscopy (EVS) and polarization-modulated IR reflection absorption spectroscopy (PS) are compared and analyzed. Both techniques have been used with a tunable diode laser to obtain quantitative reflectance spectra of adsorbed CO on single crystal Ni. System calibration for absolute accuracy is described. The reproducibility of EVS and PS is compared by using both to study the same sample on two different days. The spectra cover the 1800-2160-cm(-1) range and span the CO vibrational frequency. For spectroscopy of CO, EVS is more sensitive. The integrated IR absorption of c(2 x 2) CO on Ni(100) measured with PS agrees with previous measurement.
D K
DK
Lambert