Variable Rowland radius laboratory vacuum surface-sensitive x-ray absorption fine structure spectrometer
- Korea Research Institute of Standards and Science, P.O. Box 102, Yuseong, Daejeon 305-600 (Korea, Republic of)
A new laboratory x-ray spectrometer for surface-sensitive extended x-ray absorption fine structure [(S)EXAFS] and surface-sensitive x-ray absorption near-edge structure [(S)XANES] measurements is described. The spectrometer employs a 12 kV mA rotating anode generator. It has a monochromator equipped with a set of exchangeable curved crystals of Johann or Johansson type with different cell parameters, orientations, and Rowland radii. The computer controlled movement system based on nine stepping motors allows all the main elements of the spectrometer to be positioned freely relative to the x-ray source and gives an opportunity to use sophisticated scanning modes (for example, a mode with a focus spot position on a sample surface instead of an exit slit). The whole x-ray beam line is completely enclosed in a vacuum chamber that is directly connected to the x-ray generator, thereby preventing the absorption of x rays in the air. This layout allows a wide x-ray photon energy range from a few keV up to dozens of keV. A registration of x rays transmitted through the sample with proportional counter- and photoelectrons emitted from the sample with channeltron is used to carry out bulk- and surface-sensitive measurements, respectively. Using a 25x200 kV mA power regime of a rotating anode x-ray generator, a photon flux of 2.5x10{sup 5} counts/s was registered at the Cu K edge, where the energy resolution was about 5 eV. High near surface sensitivity is demonstrated by the EXAFS spectra of Cu K and Hf L{sub III} edges measured from 3 nm Cu and Hf oxide films.
- OSTI ID:
- 20953270
- Journal Information:
- Review of Scientific Instruments, Vol. 78, Issue 2; Other Information: DOI: 10.1063/1.2669591; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
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