Potential of the INEL X-ray position-sensitive detector: a general study of the Debye–Scherrer setting

The INEL diffractometer, equipped with a CPS120 curved detector and set up in a Debye-Scherrer geometry, is a unique tool for carrying out powder diffraction studies on air-sensitive and/or small-volume samples. Although it has routinely been used in powder diffractometry because of its minute acquisition times, its accuracy in d-spacing and intensity measurements has not been clearly demonstrated before now. Concerning the d spacings, proper linearization of the CPS120 with a cubic Na₂Ca₃Al₂F₁₄ standard allowed a mean δ_2θ difference of 0.006°. Intensity accuracy was measured with different highly and poorly absorbing samples. The accuracy is fairly good for the latter but poor for the former, except when special procedures such as the dilution of the sample with boron powder are used. A Rietveld calculation carried out on TI₄V₂0₇ showed a very good agreement between the INEL Debye-Scherrer-geometry results and those obtained with a Philips diffractometer and Bragg-Brentano geometry.