Simultaneous determination of specimen temperature and specimen displacement in high-temperature X-ray diffractometry applying Bragg-Brentano geometry

Temperature uncertainty and unknown specimen displacement are the most severe errors in high-temperature X-ray diffractometry, in particular when using a strip heater mounted on a Bragg-Brentano goniometer. A method is presented that enables the simultaneous determination of the specimen displacement and the temperature of the sample. The method splits the determination of the aberrations into two steps: at room temperature and at elevated temperature. It is based on the use of a reference material as an internal standard. An experimental example applying the method to a specific material is given, and shows that the method provides correct data.