Pair distribution function analysis of X-ray diffraction from amorphous spheres in an asymmetric transmission geometry: application to a Zr_58.5Cu_15.6Ni_12.8Al_10.3Nb_2.8 glass

A method for the calculation of the pair distribution and structure functions from X-ray intensity data obtained with an area detector for an off-center incident X-ray beam on an amorphous sphere is presented. Error propagation for converting from the structure function to the pair distribution function is also described, including a summation series approach to treat the error from a high-q truncation. A Zr_58.5Cu_15.6Ni_12.8Al_10.3Nb_2.8 glass (Vitreloy 106a) is used to demonstrate the techniques. In particular, the semi-analytical corrections presented to calculate the effects of secondary scatter within and asymmetric transmission through a spherical sample are verified.