Determination of crystal orientation by an area-detector image for surface X-ray diffraction

A new method of calculating the crystal orientation matrix (U matrix) of a specified sample using two-dimensional X-ray diffraction spots that are recorded on an area detector is presented. In this way, the U matrix is calculated using at least three two-dimensional diffraction spots of known two-dimensional indices, which provide the projection of the crystal truncation rod onto the detector. The method, in the case of surface X-ray diffraction measurements with an area detector, enables easier and faster sample alignment than the conventional method to determine the U matrix.