The first-order Stark effect is observed for CO adsorbed on Ni(110). The Stark tuning rate is (1.1 ± 0.4) × ${10}^{-6\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$/(V/cm). The present measurement agrees with a model calculation. By electric field modulation of the resonant vibrational frequency of adsorbed molecules, the derivative vibrational spectrum can be measured. The spectra of CO on Ni(110) obtained are consistent with published electron-energy-loss spectra. The new technique is zero background, surface selective, and can be used in UHV or atmospheric pressure.

• Received 14 March 1983

DOI:https://doi.org/10.1103/PhysRevLett.50.2106