Absolute Measurement of Structure Factors of Si Single Crystal by Means of X-Ray Pendellösung Fringes

Structure factors of Si single crystal were measured absolutely by means of Pendellösung fringes, the method being entirely free from the ambiguity of extinction. The causes of slight but systematic discrepancy recongnized in the previous work (N. Kato and A. R. Lang: Acta cryst. 12 (1959) 787) were elucidated. For eliminating the causes of errors, the section pattern was used. The structure factors obtained agree well with Göttlicher et al 's values which were obtained by the usual X-ray method. This implies that the Debye-Waller factor to be used in dynamical diffraction theory should be the same one as the factor adequate to the kinematical theory. The Debye temperature \(\varTheta_{M}\) for X-ray diffraction is determined to be 538°K. at room temperature. Based on the structure factors obtained, it is also concluded that a kind of scattering factor f ε of the bonding charge assumed at the middle of the -bond can be represented in the form f ε =0.45exp -13(sin θ/λ) ² .