A (2+3)-Type Surface Diffractometer: Mergence of the z-Axis and (2+2)-Type Geometries

Abstract

It is shown that the addition of an azimuthal detector rotation to a (2 + 2)-type diffractometer makes it fully equivalent to a z-axis type. Using this equivalence, the geometric correction factors for this (2+3)-type diffractometer, which are needed to obtain structure factors from measured integrated intensities, are derived. The (2 + 3)-circle diffractometer combines the ideal resolution behaviour of a z-axis diffractometer with the mechanical simplicity and range of a (2 + 2)-circle diffractometer. For sample alignment, two additional degrees of freedom are needed, leading to a total of seven circles.

Silicon Σ13(501) grain boundary interface structure determined by bicrystal Bragg rod X-ray scattering

“…Some BCTRs were measured with rocking curves using a point detector with fixed angular resolution (scintillation detector) and others using the stationary mode with the area detector for which the large acceptance angle of the detector collects the entire in-plane component of the rod for a given L. The integrated intensity is obtained using the box subtraction method presented in [30] for the area detector or conventional peak integration for the rocking scans. Structure factors were derived from the integrated intensities by application of geometrical correction factors [31,29]. In addition, a correction factor that accounts for attenuation of the beam through the sample was calculated by numerical integration.…”

“…The sample was mounted on a (2+3)-type diffractometer [29] at the I07 beamline of the Diamond Light Source. A wavelength λ = 0.7276Å was chosen because the x-ray beam penetrates the sample at this high energy but the quantum efficiency of the PILATS 100K (Dectris) area detector is also high enough.…”

Stability of the polar {111} NaCl crystal face

“…The experimental setup consists of a cell in which the crystal surface can be examined in a well-controlled atmosphere. 11 This cell is coupled to a ͑2+3͒ diffractometer 12 operating in a vertical geometry in the case of the DUBBLE beam line and to a horizontal Z-axis diffractometer 13 in the case of ID03. To establish equilibrium between crystal and vapor, the system was left for at least 15 min before every measurement.…”

Surface structure of Bi2Se3(111) determined by low-energy electron diffraction and surface x-ray diffraction

“…X-ray photoemission spectroscopy performed in the LEED chamber did not show any detectable contaminations. SXRD data were taken at beamline I07 of the Diamond Light Source, using 20 keV X-rays and a UHV chamber mounted on a large '2+3' diffractometer [18]. Scattered X-rays were collected using a two-dimensional detector (Pilatus) enabling fast data acquisition.…”