A comparison of the KOSSEL and the X‐ray Rotation‐Tilt Technique

Abstract

There are world-wide efforts to analyse micron regions of compact samples by means of X-ray diffraction ("X-ray Microdiffraction"). Two micro diffraction procedures, the KOSSEL technique excited by electron or synchrotron radiation beams and the new X-ray Rotation-Tilt Method (XRT), are compared to show their possibilities and limitations. Some selected examples of new applications are presented.

Effect of the cutting technique on the residual stress distribution of cut edges in FeSi3 transformer sheets

“…Due to the high diffraction angle, the reflections have a larger distance between the K α1 and K α2 reflections, thus, a high dispersion of the doublets, which results in a high sensitivity to the lattice distortions [16]. In special cases, the accuracy of the Kossel technique for the determination of lattice constants is given as Δa/a =10 -5 to 10 -6 [17,18]. An estimate of the dislocation density is possible in the range of 10 7 to 10 10 cm -2 [20].…”

Precise determination of residual stresses in FeSi3 electrical sheets in the vicinity of laser scratches with high lateral resolution

“…The lateral resolution of the spot is restricted to 100 µm on the sample, thus no high lateral resolution of the distribution of residual stresses is possible. Additionally, it was shown that the inclination of the sample against the detector plane (necessary to detect the {013} reflections) and the movement of the "orbital unit" [14][15][16] produced small errors at the reflection positions which cumulated to large errors for the calculation of lattice strain. Therefore the XRT method is not suitable for high precision determinations of absolute stresses.…”

“…Due to the high diffraction angle, the reflections possess a larger distance between the K α1 and K α2 reflections, thus, a higher dispersion of the doublets, which results in a higher sensitivity to the lattice distortions [13]. In general, the accuracy of the KOSSEL technique for the determination of lattice constants is given with ∆a/a =10 -5 to 10 -6 [15].…”

“…Any change of the structure has to be avoided. Therefore, the X-ray Rotation Tilt method (XRT) [14] was applied for the first investigations in order to determine the residual stresses [15] in the laser scribed electrical steel sheets. For this method the forsterite layers do not need to be removed, thus, no special sample preparation is necessary.…”

Two-dimensional small-angle X-ray scattering from as-grown and heat-treated synthetic quartz

“…6 suggest that SAXS optics are suitable to obtain reliable fractions of the Kossel pattern from a thin single crystal as a function of external variables such as temperature. Similarly to the Kossel and X-ray rotation-tilt techniques (Bauch et al, 2003), this method can be optimized to record changes in shortrange periodicity of the crystal lattice, such as variation in lattice parameter and formation of structural defects induced by irradiation, together with the SAXS patterns using single experimental setting.…”