Total-scattering-based automatic centring of capillary samples within powder diffractometers

Abstract

A computer‐controlled method for the automatic mechanical centring of a powder capillary sample onto the rotation centre of a powder diffractometer, using total scattering of the radiation beam into one‐dimensional or two‐dimensional detectors, and only a 90° rotation of the sample stage, is described. This method is particularly useful for situations where powder capillaries are within non‐ambient experimental apparatus or loaded via an automatic sample changer. Irregularly shaped samples, potentially subject to absorption effects, are aligned and centred on the sample's `scattering centre'.

In Situ Powder X-ray Diffraction, Synthesis, and Magnetic Properties of the Defect Zircon Structure ScVO4−x

“…Room temperature data sets were collected in the 2θ range 10° to 90° in 0.0083° steps using a zero background quartz sample holder. All diffractograms were analyzed by the Rietveld method using GSAS …”

“…Powder neutron diffraction data were collected on the medium resolution 800 wire diffractometer C2 operated by the National Research Council Canada at Chalk River at room temperature. , Diffractograms were measured using a cylindrical vanadium sample container and neutron wavelengths λ = 2.37043(5) Å (5° ≤ 2θ ≤ 85°) and λ = 1.33003(2) Å (35° ≤ 2θ ≤ 115°) at 0.05° increments. Rietveld refinements against powder X-ray and two powder neutron data sets were performed with GSAS .…”

In situ high-temperature X-ray and neutron diffraction of Cu–Mn oxide phases

“…The tubes were sealed with a reduced pressure of air inside to maintain a pressure near one atmosphere during hightemperature testing. In situ neutron diffraction was performed at the Canadian Neutron Beam Centre, NRC, Chalk River, on the C2 Spectrometer equipped with a silicon monochromator [X, Y] [ 24,25]. Diffraction patterns were acquired for 0°\ 2h \ 120°using two different wavelengths: 1.32927(6) and 2.37083(13) Å .…”