High-precision determination of structure factorsFhof silicon

Structure factors $F_h$ of perfect silicon crystals have been measured at room temperature for a number of 16 reflections up to the (880) for both $\mathrm{Ag} K{\alpha }_1$ and $\mathrm{Mo} K{\alpha }_1$ radiation. The measurements are based on the analysis of the fine oscillatory structure of Laue case rocking curves. The data are consistent with earlier results obtained with the pendellösung method using wedge-shaped crystals, but probable errors were reduced to below the 0.1% level. An important advantage of the new method is the significantly reduced ideal crystal volume of typically 0.5 ${\mathrm{mm}}^3$ for silicon and material with similar absorption, which makes it applicable even if large perfect crystals are difficult, or practically impossible, to grow.