HIGH-TEMPERATURE X-RAY-DIFFRACTION - SOLUTIONS TO UNCERTAINTIES IN TEMPERATURE AND SAMPLE POSITION

Methods of minimizing the uncertainties in temperature and position that are inherent in high-temperature X-ray powder diffraction measurements made using strip heaters are discussed, with particular reference to the Anton Paar HTK 10 heating stage. Modification of the strip geometry is recommended to largely eliminate temperature gradients across the sample area and the use of the strip heater as an internal standard is recommended to eliminate positional uncertainties and test temperature calibration. Data on the thermal expansion of Al2O3 are used to evaluate the success of these procedures.