Fast Crystal Domain Mapping
Spectrum of a silicon crystal (fixed with a Ca-containing clay). The diffraction peaks, marked as grey regions F1 … F4) are the fingerprint of a specific crystal orientation. If this pattern changes at another location of the sample, the Si is not a single-crystal.
Crystalline structures regularly cause diffraction peaks when analyzed with X-rays. X-ray Diffractometry (XRD) is the method of choice for characterizing crystals and identifying their orientation. The setup of the M4 TORNADO micro-XRF spectrometer (focused polychromatic X-ray beam, large solid angle of detection) makes the detection of diffraction peaks (Bragg peaks) very likely but makes their quantitative analysis difficult. Purely qualitative analysis; for example seeing the positions, sizes of, and borders between, crystal domains already tells a lot about the samples.
There is no quicker way to show qualitative changes in diffraction patterns over such large sample areas with this spatial resolution than with the M4/M6 technology.
Crystal domain distribution in a large welding joint. 6.6 x 5 cm² measured in less than 8h with a spatial resolution of 20 µm. Size and direction of crystal domains in the welding joint correlate with the cooling gradient. Also, the different steels show different crystal domain properties.
Twinning in a NdGdO3 crystal. The simultaneous measurement of stoichiometry (inset at the top-right) and crystal domain distribution is a vital step for quality control of manufactured crystals.