Modeling of Bragg intensity profiles. 1. Allowance for crystal mosaicity

The model of the instrumental function of a four-circle X-ray diffractometer suggested earlier [Chulichkov et al. (1987). Kristallografiya, 32, 1107–1114] is complemented by the introduction of the crystal mosaicity. This improved model is used to develop a method for the reconstruction of the mosaicity function profile f(ω) from the experimental intensity profile I(ω) measured on a diffractometer. The method consists of the reduction of the experimental I(ω) distribution to the form it would have if it were measured on a diffractometer with an instrumental function close to the δ function. The suggested method for determining f(ω) is tested on Si crystals with dislocation densities N_d = 3 × 10¹⁰ and 2 × 10¹¹ m⁻².