QUANTUM DELOCALIZATION OF H ON PD(110) - A VIBRATIONAL STUDY

The vibrational spectra of H on Pd(110) at 90 K have been measured in the low-H-coverage region, by using high-resolution electron-energy-lo ss spectroscopy. Three dipole-active loss peaks associated with H adat oms were observed at 87-89, 96-100, and 121-122 meV. A model calculati on based on the delocalization of H was made, which gives the energy p ositions and relative intensity variation of the two loss peaks in the range of 87-100 meV for different H coverages. There is a reasonable agreement between the calculated and experimental results. It is concl uded that vibrationally excited H atoms on Pd(110) are described by th e delocalized model.