Oscillations in the valence-band photoemission spectrum of the heterofullerene C59N: A photoelectron interference phenomenon
نویسندگان
چکیده
The intensities of the two strongest low-binding energy features in the valence-band photoemission spectra of C59N have been observed to oscillate as the photon energy of the exciting radiation is varied. The maxima in the intensity ratio of the two peaks occur at the same photon energies as the maxima in the intensity ratios of the highest occupied molecular orbitals to next highest occupied molecular orbitals ~NHOMO! peaks of C60. The amplitude of modulation of the ratio is remarkably similar in both cases. Since the nature of the filled and empty states involved in the photoemission process are different for C59N compared to C60, the current observation therefore supports the proposal that the final state is of negligible importance in the mechanism leading to the oscillations. The intensity variation instead arises from a photoelectron interference effect as a consequence of the spherical environment of the electron emitters within the molecule. @S0163-1829~99!02715-0#
منابع مشابه
Electronic structure of potassium - doped
The electronic structure of potassium-doped La@C82 has been studied with synchrotron-radiation photoelectron spectroscopy. Ultraviolet photoemission measurements indicate evolution of the valence-band states of La@C82 with increasing potassium content, but KxLa@C82 remains semiconducting for all x between 0 and 6, with a band gap of at least 0.4 eV, in contrast to K-doped C60. The valence-band ...
متن کاملExchange splitting of the three Γ ̄ surface states of Ni(111) from three-dimensional spin- and angle-resolved photoemission spectroscopy
The valence-band electronic structure of a clean Ni(111) surface is investigated by spin-resolved photoemission. At room temperature the orientation of the photoelectron spins on the Bloch sphere and the exchange splitting of surface and bulk states along the surface normal (Γ̅ ) are determined. All investigated states are found to have a sizable exchange splitting >50 meV. Since the splitting i...
متن کاملBand-gap shrinkage in n-type-doped CdO probed by photoemission spectroscopy
The influence of n-type doping CdO with In or Y has been investigated by high-resolution ultraviolet and x-ray photoemission spectroscopy. It is found that core levels and valence band features suffer a shift to high binding energy due to doping. However this shift is less than the change in the width of the occupied conduction band. This provides a direct measurement of band gap shrinkage as a...
متن کاملAttosecond time-resolved photoemission from core and valence states of magnesium.
We report on laser-assisted attosecond photoemission from single-crystalline magnesium. In strong contrast to the previously investigated transition metal tungsten, photoelectron wave packets originating from the localized core level and delocalized valence-band states are launched simultaneously from the solid within the experimental uncertainty of 20 as. This phenomenon is shown to be compati...
متن کاملSoft x-ray photoemission studies of the HfO2 ÕSiO2 ÕSi system
Soft x-ray photoelectron spectroscopy with synchrotron radiation was employed to study the valence-band offsets for the HfO2 /SiO2 /Si and HfO2 /SiOxNy /Si systems. We obtained a valence-band offset difference of 21.0560.1 eV between HfO2 ~in HfO2/15 Å SiO2 /Si! and SiO2 ~in 15 Å SiO2 /Si!. There is no measurable difference between the HfO2 valence-band maximum positions of the HfO2/10 Å SiOxNy...
متن کامل