Angle-resolved x-ray photoemission

ARXPD Angle-Resolved X-ray Photoemission Diffraction Similar to ARXPS and ARPEFS. The angular variation in the photoemission intensity is measured at a fixed energy above the excitation threshold to provide structural information. 

ARXPS Angle-Resolved X-ray Photoemission Spectroscopy The diffraction of electrons photoemitted from core-levels gives structural information on the surface. 

Angle-resolved X-ray photoemission spectroscopy (3, 38, 39, 49, 50) Conversion electron Mossbauer spectroscopy (4, 52-55)... 

ARXPS angle-resolved X-ray photoemission HAS helium atom scattering... 

UPS and XPS (Ultraviolet and X-Ray Photoemission Spectroscopy) and ARUPS (Angle-Resolved UPS)... 

APD, ARPEFS Azimuthal PED, angle- Same as PED resolved photoemission extended fine structure Spectroscopy of Emitted X-rays or Photons Same as PED... 

Two rather different techniques that exploit the same underlying phenomenon of coherent interference of elastically scattered low energy electrons are photoelectron diffraction [5] and surface extended X-ray absorption fine structure (SEXAFS) [6,7]. Figure 1.1. shows schematically a comparison of the electron interference paths in LEED and in these two techniques. In both photoelectron diffraction and SEXAFS the source of electrons is not an electron beam from outside the surface, as in LEED, but photoelectrons emitted from a core level of an atom within the adsorbate. In photoelectron diffraction one detects the photoelectrons directly, outside the surface, as a function of direction or photoelectron energy (or both). The detected angle-resolved photoemission signal comprises a coherent sum of the directly emitted component of the outgoing photoelectron wavefield and other components of the same wavefield elastically scattered by atoms (especially in the substrate) close... 

Ultra-violet photoemission spectroscopy (UPS) probes the density of states, and ion neutralization spectroscopy (INS) and surface Penning ionization (SPI) provide similar information with probes of ions and metastable atoms, respectively. Angle-resolved UPS can determine the valence band structure. X-ray Photoelectron Spectroscopy (XPS) provides information on chemical shifts of the atomic core levels, and this can also help in understanding chemical bonding at the surface. 

Surface analytical techniques such as Auger electron spectroscopy (27), X-ray photoelectron spectroscopy (28), and secondary-ion mass spectrometry (29) have been used to study LB films. Synchrotron radiation is a particularly powerful probe enabling X-ray near-edge structure and extended X-ray absorption fine structure to be measured. Angle-resolved photoemission studies (30) confirmed the existence of a one-dimensional energy band along the (CH2)jc chain in a fatty acid salt film. 

Solid state spectroscopy usually revolves around the determination of properties characteristic of a solid, such as the density of states in the conduction band, the position of the Fermi energy, etc. These can be probed by X-ray photoabsorption or more directly by photoemission (either angle-resolved [593] or inverse [594]) spectroscopies, in which case the initial quasiatomic state is reasonably well known since it is close to the wavefunction of a free atom, while the final state is the continuum characteristic of the solid, so that the dispersion of the wavevector k can be determined. 

Gray AX, Papp C, Ueda S, Balke B, Yamashita Y, Plucinski L, Minar J, Braun J, Ylvisaker ER, Schneider CM, Pickett WE, Ebert H, Kobayashi K, Fadley CS (2011) Probing bulk electronic structure with hard X-ray angle-resolved photoemission. Nat Mater 10 759-764... 

With the availability of intense tunable radiation in the range firom ultraviolet to hard X-rays from synchrotrons, powerful new experimental techniques have been developed to probe the structural and electronic properties of solids and surfaces. In particular, angle-resolved photoemission gives information about the electronic properties in the valence bands of solids while core level spectroscopy provides an element-specific spectroscopic tool. 

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