Background
With the MiniFlex, it is possible to select a fine focus tube (focal point size 0.4 x 8 mm²) in addition to a normal focus tube (focal point size 1 x 10 mm²) of the type generally used with powder X-ray diffractometers.
Investigation
Fig. 1 shows an overlay of diffraction peaks obtained by measuring with a normal focus tube and fine focus tube. Table 1 shows a comparison of intensity, and full width at half maximum (FWHM), which varies proportionally with resolution.
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Both intensity and resolution can be improved by using a fine focus tube. Therefore, these tubes are suitable for measuring samples with many peaks, and samples containing trace components. Fig. 2 shows qualitative analysis results, and quantitative analysis results using the Rietveld method, for a cement sample (NIST 2686 standard material). In the analysis results, there was a good match, within the error range, between the content of each crystal phase, and the standard values for NIST 2686 standard material.
Apparatus conditions:
MiniFlex600 (F.F tube), Detector: D/teX Ultra, Slit conditions: DS = 0.625°, SS = 8 mm, RS = open, Incident side and receiving side Soller slit: 5°, Incident height limiting slit = 10 mm
Measurement conditions:
Scan range: 2θ = 5 ~ 90°, Step width: 0.02°, Scan speed: 5° / min. (about 18 min.)