Filtyp
High resolution photoemission applied to the C 1s and Rh 3d core levels has been used to investigate the adsorption sites at low temperature of CO on the Rh(111) single crystal surface as a function of CO coverage. Two different sites are found to be occupied by the CO molecules. At coverages up to 0.5 monolayers the majority of the molecules are found to adsorb in on-top sites whereas at higher c
The electronic structure of Ba0.6K0.4BiO3-y single crystals has been studied using a scanning photoelectron microscope with a lateral resolution in the one micrometer range. It is possible to change the oxygen content (y) and convert the surface from the metallic to the dielectric state presumably by breaking the Bi-O bonds by using the focused zero-order light to irradiate the sample surface. The
The influence on O 2p holes in single crystalline Bi2Sr2CaCu2O8 upon the interface formation to Cu, Ag and Au has been studied by O K edge X-ray absorption measurements. It was found that Cu reduces the amount of doping induced O 2p holes significantly in the vicinity of the interface, whereas Ag and Au gave a much smaller reduction of these states. Photoemission spectra confirmed previous finding
Semiconducting Ba0.9K0.1BiO3 and superconducting Ba0.6K0.4BiO3 single crystals cleaved in situ have been studied by core level and valence band photoelectron spectroscopy and O K edge x-ray absorption spectroscopy. It was found that the general shape of the valence band spectrum agrees with the shape predicted by band structure calculations, but the intensity near the Fermi level was lower in the
The O 1s core level of three different Bi-Sr-Ca-Cu-O superconductors has been studied by means of high-resolution x-ray-photoelectron spectroscopy (XPS) and x-ray-absorption spectroscopy (XAS). The O 1s XPS spectra could be decomposed into three components that were unambiguously assigned to the emission from the three different oxide layers in the crystal structure. These are, in order of increas
Alkali-metal-induced satellite peaks associated with the K 3p and Al 2p core levels have been measured with photoemission for K/Al(111) and K/Al(100) under both low- and room-temperature preparation conditions. For low-temperature deposition we observedddd loss peaks in good agreement with electron-energy-loss spectroscopy studies of analogous systems which we assign to the excitation of collectiv
For soft x-ray fluorescence spectroscopy with selective energy excitation, it is desirable to have maximum flux at moderate resolution. A plane grating monochromator with varied line spacing can be used in the convergent beam of an ellipsoidal focusing mirror to provide moderate resolution with a large collection angle and minimum number of reflecting surfaces. We determine the design parameters f
Insertion devices on the third-generation 1.5 GeV electron storage ring MAX II will subject the grazing incidence mirrors and gratings of new soft x-ray beamlines to high thermal loads. These thermal loads will cause distortion in the optical surfaces which can be reduced to acceptable levels by the proper choice of substrate material and cooling. A finite element analysis of the temperature varia
The performance of a scanning photoelectron microscope at the MAX I storage ring in Lund is presented. The microscope utilizes undulator radiation in the energy range 15-150 eV and is comprised of a plane-grating monochromator with a Kirkpatrick-Baez objective and a gracing incidence ellipsoidal focusing mirror. The instrument with its high photon flux, 109-1010 photons/s, and narrow bandwidth, be
High resolution core level photoemission measurements are reported of the binding energy shifts of the 3d core level of Mo, Rh and Pd atoms in interfaces between these 4d metals and alkali metals. The core level binding energies of the interface 4d atoms are found to be almost equal to those of the clean surface atoms for Mo and Rh. For Pd a large alkali induced shift towards higher binding energy
Core level binding energy shifts from approximately three layers of different alkali metals deposited on Pd(111), Pd(100), Rh (111), and Rh (110) are presented in order to demonstrate how the packing of the substrate surface affects the layer-resolved alkali core level binding energy shifts. It is found that a more open surface induces a larger alkali core level binding energy shift. It is shown t
Utilizing monochromatized synchrotron radiation strong photoemission enhancements in the valence-band region and the Cu 3p core level have been measured in the vicinity of the Cu L3 threshold of Bi2Sr2CuO6 and Bi2Sr2CaCu2O8 superconductors. For both the valence-band and the Cu 3p level in both crystals the satellite structures show the strongest enhancements. The line shapes of these enhanced sate
The dynamics of the temperature induced transformation between low and high temperature adsorption phases of Rb on Al(111) has been followed by high resolution core level spectroscopy. Particular emphasis has been paid to the order-preserving transformation between the low and high temperature Al(111)-Rb-(√3 × √3)R30° structures in which Rb atoms occupy on-top and substitutional sites, respectivel
A photoemission study of the Be(112̄0) surface carried out at a sample temperature of 100 K is reported. A surface shifted Be 1s component, having a shift of - 410 meV, is resolved on this surface. The extracted surface to bulk intensity ratio indicate that this component originates from atoms in the surface layer only. This is opposite to previous observations on both the close-packed
Core-level binding energy shifts of Cs induced by changes in the surroundings of the Cs atoms are measured for two different Cs core levels, 5p and 4d, and are found to be different for these two levels. The surface core-level shift of Cs is found to differ by 25 meV between the two levels. In the case of the Cs core-level shifts between bulk Cs atoms and Cs atoms at an interface between Cs and an
Photoemission from different alkali core levels (Na 2p, K 3p, Rb 4p, and Cs 4d) has been studied for thin alkali films deposited on four different 4d metal surfaces: Mo(110), Rh(111), Rh(110), and Pd(100). Alkali atoms at the interface, the bulk, and at the surface of the adsorbed alkali film are found to have different core-level binding energies. It is found that the core-level binding-energy sh
The low temperature coadsorption of Na and Rb on an Al(111) surface is examined with a combination of LEED and core level photoemission spectroscopy. We observe LEED pattern sequences and alkali core level binding energies which are consistent with a net total alkali coverage and can be explained by Na-Rb repulsion, segregation, and islanding, though other models cannot be definitely excluded.
The synchrotron-radiation-induced Auger and photoelectron spectra of the xenonlike ions I- (in CsI), Cs+ (in CsI), Ba2+ (in BaF2), and La3+ (in LaF3) have been measured in the vicinity of the M4,5 absorption edges of these ions. It is shown that the spectra of La and Ba measured at 3d10→3d94f resonances exhibit a very intense 4f-spectator structure which changes its energy and intensity with the e
High resolution measurements are reported of the surface core-level shift of the 3d level for the Rh(111), Rh(110), Pd(111), Pd(110), and Ag(111) single-crystal surfaces. These measurements and earlier ones for the Mo(110), Rh(100), and Pd(100) surfaces are analyzed by ab initio calculations of the surface core-level shift. The calculations are found to reproduce well the trends of the experimenta
A high-resolution photoemission study of the Be (101̄0) surface, at a sample temperature of 100 K, is reported. Three surface-shifted Be 1s components are revealed having shifts of -700, -500, and -220 meV. These are interpreted as originating from the first, second, and third plus fourth atomic layers while the bulk signal originates from the fifth and deeper layers. The surface layer shift for t
