Flat-plate single-crystal silicon sample holders for neutron powder diffraction studies of highly absorbing gadolinium compounds

A flat-plate single-crystal sample holder is used to place a thin layer of highly absorbing samarium and gadolinium compounds in a neutron beam and obtain Rietveld refinement quality diffraction data in a modest time. Demonstration data are presented on two intermetallic compounds, Sm₃Ag₄Sn₄ and Gd₃Ag₄Sn₄, and it is shown that both structural and magnetic information can be derived from the diffraction patterns.

Convenient off-line error quantification and characterization of concentricity of two circles of rotation for diffractometer alignment

To ensure concentricity of the θ–2θ rotation stages, but with a very limited 2θ range of rotation, an alignment technique using two dial gauges mounted at right angles to each other (X and Y axes) is described.

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

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.